The Definitive Guide to the Foot in the Door technique (learn how to 2X your conversion rate)

Egor Driagin

(This is the 2nd article in the 8-part series where I explore Cialdini’s 7 (not 6!) principles of persuasion and how best to sequence them).

In case you missed it, here’s Part #1: How to make reciprocity work online: 14 surprising insights

There is one technique that does wonders for your conversion rates. As I am about to show you, you can use it to:

I am talking about the foot in the door technique. The reason why it works is that it utilises an effective persuasion mechanism called the commitment and consistency principle.

Read on if you want to find out how to achieve similar results for your business.

What is commitment and consistency principle?

Commitment and consistency principle is based on the theory that we, humans, want to appear consistent to ourselves and to others. Sometimes we alter our attitudes to be in line with our actions (as explained by the self-perception theory).

This is where persuasion experts step in.

By making people to commit to something, we might change their attitudes. This makes it more likely that they will comply with other related requests in the future. A classic example comes from a 1966 study by Jonathan Freedman and Scott Fraser.

Researchers asked a group of residents to support a safe driving campaign. This meant installing a large (6 feet by 3 feet) sign, stating “DRIVE CAREFULLY” on their front lawn. Only 17% of residents agreed to do so, but this number jumped to 76% for another set of residents.

What caused that difference?

Two weeks earlier researchers approached that group of residents with another request. They asked them to install a small sign in their window that read “BE A SAFE DRIVER”. People easily said “yes”. What residents did not realise is that this first commitment would make them see themselves as the type of people who support such causes as safe driving. Two weeks later, to appear consistent with their past behavior (and a newly acquired self-image) they had to agree with a larger request, too.

That’s the essence of the foot-in-the-door technique: compliance with a modest request leads to compliance with a larger request.

Now let’s think about how you can apply that principle to your online marketing!

What is so powerful about it?

Consistency and commitment principle is powerful because not only can you increase immediate conversions within your sales funnel, but also alter your customers’ attitudes towards your brand. As you will see in the studies below, this could go as far as turning your dissatisfied customers into satisfied ones. This means lower churn rate and higher lifetime customer value.

Will it work for you and how can you maximise your chances of success?

As with the norm of reciprocity, you are very unlikely to be able to manipulate your customers. When applying this principle online, people would think more deliberately about requests that they comply to. So, unless your request might add some real value to their lives, people will likely reject it. Yet, you can still use this principle to gradually guide them towards the target request. The one that will help them to live a better life and make you money.

Commitment and consistency principle has the greatest effect when one’s self-image is affected by his/her previous actions. According to Cialdini, for the highest chance of a commitment affecting one’s self-image, it needs to be:

Not to bore you with dry theory, we will jump straight into some examples. Today I am considering 4 main use cases for this technique: email sign-up, user onboarding, check-out optimization and lead generation. Where relevant, I will cite research by Cialdini and his colleagues. Jerry Burger’s meta-analysis of existing research on the Foot-in-the-Door technique deserves special attention.

Email sign-up

Here’s what the standard email popup looks like:

While great, there is a psychological process that interferes with our goal of getting a visitor’s email address. It’s called psychological reactance. It occurs when people perceive a threat to their sense of personal freedom and choice. When we become aware of an effort to reduce our freedom (eg. we feel we are being forced to do something), we often respond in such a way that will re-assert that freedom. In that case, we will close the pop-up window.

It’s a completely different story when we offer our readers an opportunity to sign up for our email list. Let’s consider SnackNation’s example. They offer their readers an opportunity to sign up for a newsletter within their popular article, “121 Proven Employee Wellness Program Ideas For Your Office”.

When clicking “Download this entire list as a PDF”, users are making an active commitment that does not feel coerced (ie. it was their free choice). This increases the chances that they will finish the sign-up process. When SnackNation changed a forceful pop-up for an uncoerced opportunity to get a PDF checklist their subscription rate increased by 195%. From 20 subscribers per week to 59.

Moreover, entering your first name and an email address requires a certain amount of effort (tick this one, too). This gives SnackNation not only a chance to get subscribers, but also make related requests in the future such as a webinar sign-up (which is a larger commitment).

“Remember you signed up for this PDF checklist? We know you are the type of person who cares about employees’ well-being. Why not sign-up for our free webinar that will help you with exactly that?”

Apparently, that’s what they do:

Now, using research on the use of commitment and consistency principle, I will walk you through some questions. They will help us to understand if SnackNation is doing a good job.

Does it tie a visitor’s first commitment to her self-image?

First of all, we know that, to be effective, the first commitment needs to insert a desirable (from our point of view) self-image into the person. So, we might want to improve this page by tieing a person’s identity to the action.

It could look like this:

Does your second request seem like a logical progression of your first request?

Burger found that when a second request seemed like a continuation of the first request, participants were twice as likely to comply relative to the control groups.

In SnackNation’s case a webinar on wellness seems to be a logical progression of the first request to download the wellness program report. Well done guys!

On the other hand, Decathlon, a global sports retailer, fails on this one. As you enter their website, you are being presented with a standard email sign-up form. It promises that upon entering your email address, you will receive sport advice and offers.

From my point of view, the logical progression would have been to ask me to confirm my email address, so that I can start receiving those offers. Instead, their second request is to create an account at MyDecathlon (I am still not sure what that is):

In other words, to complete that enormous sign-up form with several tabs:

Decathlon’s signup process is likely to be ineffective because psychological reactance might kick in. A user might feel that Decathlon purposefully omitted any information about account creation. They made the pop-up form seem like a newsletter sign-up, so that users don’t realise that they will have to go through a lengthy sign-up process, all before receiving any of the promised perks. As we know from reactance theory, when we feel manipulated, we will act in an opposite way to re-assert that freedom (ie. not sign up).

But there is another reason why Decathlon’s sign up process might be failing. It violates the rule of reciprocity…

Are you taking and giving back or just taking and taking more?

We know that when we apply the principle of commitment and consistency, compliance with a small request leads to compliance with a larger request. Well, this is not always the case. As one study showed, when two requests are made one straight after another (and the second one is not a logical progression of the first one), the norm of reciprocity might burn this whole persuasion effort into pieces.

In line with the norm of reciprocity, after people complied with the first request (put some effort on their end), they feel that the person who asked for it is indebted to them in some way. So, unless the “asker” provides something of value back first, the second request would be taken unfavourably. People would perceive it as an imprudent act that violates the norm of reciprocity and, as Cialdini says in the book, we tend to react negatively to such violators.

Note: The reciprocity norm is unlikely to backfire when the sign-up form is designed as a logical progression sequence (for example, upon signing up you are made another request, to confirm your email). This is because the second request would seem as a part of the first request, not a separate request. According to Burger, the highest risk of the reciprocity rule backfiring is when two unrelated requests are made one straight after the other.

This is exactly the mistake that Decathlon is making.

First of all, upon receiving your email address, they make you a second request that is unrelated to their first request. I would have expected them to ask me for confirmation of my email address. Instead, they asked me to create an account at some unknown MyDecathlon. As we saw this involves filling out several, complicated forms.

I have also put some effort on my end, I provided an email address. So, if the second request does not logically progress from the first one, I would at least expect to get something of value in return for my contact details. Unfortunately, this is not the case. Now, I feel that the reciprocity norm has been violated, causing a negative reaction on my end.

Compare this to what Reebok is doing.

You just comply with their first request (enter your email address) and boom!

A free coupon offer straight to your inbox.

Obligations on both ends have been fulfilled, now I am ready to consider any other requests from them.

Similarly, SnackNation provides you with value once you complied with their first request. Upon entering your contact details you expect to receive a PDF-checklist in return.

The copy on the next page informs you that the PDF was sent. So, SnackNation fulfilled their obligations and it’s ok to make a second request (webinar sign-up).

So, what should a firm like Decathlon do if ultimately they want you to create an account with them?

Well, they could have informed us that we would need to create an account before receiving any offers.

Then, copy in the email would seem like a logical progression of what has been offered in the pop-up.

Alternatively, they could take an approach where the first commitment would be tied to a person’s identity. They could offer a 60-second quiz, making users answer a number of questions about themselves.

The quiz would allow them to find out more about the person. This in turn would give them an opportunity to use that first commitment (quiz completion) as a segway to registering an account at MyDecathlon.

Here’s what it could look like:

However, there is also another factor that we need to consider when dealing with the norm of reciprocity. It’s timing.

Are you timing your requests or trying to feed the whole pie?

One study has shown that the reciprocity norm lasts only a few days, at least for the kinds of favors typically examined in social psychology experiments (for example, receiving a soft drink). That is, the obligation people feel to return a small favour appears to dissipate after a short period of time. So, if you are making two, unrelated requests, you might overcome the negative effects of the norm of reciprocity by simply making these requests on separate days.

Research is inconclusive on how many days need to pass by for the norm of reciprocity to lose its effect. In a recent study a lapse of 2 days was sufficient to produce a more favourable effect than when there was no delay at all. This means that if Decathlon employed the quiz change I described above, it might have been safer to send the follow-up email 2 days later.

What are you communicating about people’s likelihood to comply with your request?

A fourth consideration we need to make is social proof. It was found that if a person perceives the type of request you are making as the one only few people comply to, they would be less likely to commit to it. This is exactly what SnackNation might be sub-communicating with their “The number of seats are limited…” copy. We are not being told how many seats are left (or have been reserved).

This could have been interpreted as a “needy” attempt to get at least a few webinar attendees (unfavourable social proof). So, from the research on commitment and consistency, it might have been safer to reframe this last bit as “XX caring HR managers have already signed up” (I assume that a good number of people actually signs up).

Pro Tip: Customise your email pop-ups

In case you don’t have time to create customised lead magnets to every single one of your posts (or you’re afraid the bonus won’t be noticed), you could test customising your standard pop-up box.

Instead of making a sign-up request straightaway, you could re-frame it as a question. Here’s an example of how Thrive Themes did it:

They ask you a question instead of pushing the sign-up form on you. The sub-headline, “Let us know, maybe we can help!” reinforces the idea of helpfulness vs. pushy-ness. These two elements reduce the psychological reactance. Now the user can consciously pick the goal they are interested in (making an active, somewhat effortful commitment that does not feel coerced).

And only after that she is being presented with a request.

With the first commitment having been made, the reader’s self-perception can now be framed as “I want to design a cool website, I just chose it as a selection”.

I asked Hanne Vervaeck, the marketing team lead at ThriveThemes, about their results:

We were able to get our conversion rate up from 5.5% (the control) to an impressive 11.7% by changing from a simple opt-in to a multiple choice opt-in form.

Hanne Vervaeck -Marketing Team Lead at Thrive Themes

It doubled their conversion rate. Very impressive indeed.

User onboarding

Similarly, Duolingo uses the principle of consistency & commitment to convert visitors into active users. Everything starts with a declarative statement, “I want to learn…” where a visitor needs to choose a language (an active commitment).

Straight after that, Duolingo asks me to decide how much I want to commit to language learning (another active commitment).

This is very smart as then they can send me emails with “remember, you set this goal for yourself”. I checked it and that’s exactly what they do:

Again, using the knowledge from Burger’s meta-analysis, we can improve the way Duolingo gets a commitment from their users. Research has shown that labeling people can have pronounced effects on their behavior. When participants’ behavior was attributed to positive internal traits (eg. calling someone “cooperative” or “helpful”) compliance rates were higher.

(Adapted from Burger, 1999, “The Foot-in-the-Door Compliance Procedure: A Multiple-Process Analysis and Review”. Combined results of 3 studies that experimented with labeling.)

Similarly, Duolingo could label users based on the commitment they made. If I chose “insane” as my commitment level, they could show me this message:

Supposedly, that label would make me more likely to keep using the app on a daily basis.

In the past, the commitment part was pushed further down the onboarding process (you can see the full overview by Samuel Hulick here). The idea was that they provided some “aha moments” first and then requested the user to make a commitment.

It’s interesting that they pushed it towards the beginning of the funnel. We will discuss why this might have been a bad choice in the 8th part of these series where we discuss sequencing.

Another great example comes from Naked Wines. Before you can use their services, they screen you on whether you would be a good fit for them.

Let’s do it!

Now, I told them I consider myself to be a wine enthusiast who would prefer a wine with a story. I have not only made several declarative statements about who I am, I have fully laid out how they can tie up my identity to their marketing.

To reward or not to reward?

There is mixed evidence on how offering extrinsic rewards affects effectiveness of the commitment and consistency principle. It’s important to notice that neither Duolingo nor Naked Wines offer any incentives in return for commitments we are making (Naked Wines gives you a voucher, but it has not been said in the copy).

Generally, studies have shown that when we are rewarded for a commitment, we are less likely to comply with a subsequent request. This is because we attribute our initial commitment to the reward, not to our internal qualities (e.g. being “determined” or generally liking certain types of wine). The greater the reward, the less committed the person is to the act (according to a study by Kiesler and Sakumara).

With that said, all these studies used money as an extrinsic reward. This is rarely the case with our online marketing activities. Instead, we offer ebooks, PDF checklists, etc. Those types of incentives have not been explored in academic research. I personally believe that ebooks and PDF checklists are a sufficiently small reward for a person to still feel committed to their action.

So, ideally you would not use them. For example, there is no way I would attribute my commitment to Duolingo learning to anything external. It’s 100% clear that I made this commitment because I want to learn a language. This gives them the full power to nudge me to stay committed to that goal (hence, use the app).

However, it should not hurt too much for the standard perks we use in online marketing. (Plus, as we will explore later in this article, rewards can strengthen our commitment). Testing is the only way to answer this question with certainty though.

Optimisation of a check-out funnel

You have probably already read about Barack Obama’s 2012 presidential campaign. The team behind it re-designed the donation form using the commitment and consistency principle. This resulted in a 5% increase in the conversion rate, adding millions of incremental dollars.

They split the check-out process into 4 steps, thus splitting the target request to donate into a series of smaller commitments. It worked.

What was missed in other overviews of this campaign is the way copy was re-framed. Notice, the new form asks, “How much would you like to donate today?” vs “Donate now”. This again overcomes the psychological reactance, showing the visitor that there is no threat to their freedom. Moreover, “How much would you like to donate” transforms the first commitment into a declarative statement about a person’s intentions, prompting one to think “I(!) want to donate that much”.

Obviously, the first commitment is active as you have to select an amount, and is not effortless.

As with the campaigns above, the strength of this implementation is that it does not offer any rewards. In terms of improvements, we know that labelling could have been used to tie one’s self-image to their action. For example, upon clicking “Continue”, one might have been shown a message, saying “That’s so generous of you. We appreciate your support.”

Lead generation

Finally, the principle of commitment and consistency can be used for getting/closing sales leads. This is not a post on sales techniques, so I will only cover how you can generate leads through digital media.

Crazy Egg offers a great example. When reading their blog, here’s a Qualaroo survey that you get. (Notice how you can skillfully use Qualaroo not just for research, but also lead generation).

Funny fact: Hiten Shah told me that at this moment their priority with this form is customer research, but we both agreed that it could as effectively be used for lead generation.

It starts with a non-intrusive question, “Would you like to know which problems on your site are driving people away?”. Notice that it also does not use any manipulative copy such as, “No, I want to keep losing customers”. Emphasis on the you again attempts to tie this commitment with our self-image.

After having made an active commitment, a visitor has to actually put some effort in and explain what her problems are.

The next question is the target request. Notice how it has been built on top of all the previous questions.

The copy remains being non-intrusive, “Would you be open to…?”.

The final step is again a logical progression of previous commitments. Giving an email address is a sufficiently small, but valuable commitment to the subsequent phone call offer.

So, again Crazy Egg combines active, effortful and non-coercive elements of commitment making for maximum effects.

I asked Hiten Shah if they used direct sales approaches (eg. asking “Would you be open to a 20 minute call about…” straightaway), and if yes, how did they compare to gradual, commitment-based approaches?

Here’s what he told me:

We have found that the direct approach is much less effective. We have tested both approaches and this one works much better. It is up to 2 times as effective in getting us people who are willing to get on the call.

Hiten Shah Founder of Crazy Egg and Kissmetrics

It’s difficult to think of how you could make all the commitments above public, but you could introduce publicity once a visitor has become familiar with what you are offering.

For example, Duolingo could prompt users to publicly share their goal of learning a new language once they completed some of the exercises.

We will cover public commitments in more depth in the next section.

Long-term impact of the commitment and consistency principle

Cialdini’s work on influence is not limited to immediate conversions. Persuasion is a different animal. The definition of persuasion, according to Cialdini is that it is focused on “the change in a private attitude or belief as a result of receiving a message.”

That leads us to the idea that we might use the principle of commitment and consistency to alter one’s attitudes towards your brand or product (or both). By making people to take a favorable stance towards your brand, you can set them on a path where it would be inconsistent to switch to your competitor.

Referral programs

Researchers explored how this effect could be induced through referral programs. The intended goal of referral programs is to attract new business. Yet, many don’t realise that, due to the effects of commitment and consistency principle, recommending a company to a friend strengthens the bond between a firm and the recommending customers themselves. This makes existing business more stable. For example, churn rate might go down.

Indeed, this is what a 2013 study has found. A group of researchers examined the impact of participating in a referral program on customers of a global cellular communications provider. They operate on a subscription-based model, so SaaS folks might find these results particularly interesting:

The principle at work is the same. After publicly recommending the company, the customers’ attitude towards the company became more favourable, to be consistent with their own behavior.

Madlen Kuester and Martin Benkenstein show that this could go as far as turning dissatisfied customers into satisfied ones. Their study showed that recommending a firm enhanced attitude and loyalty towards the recommended provider despite users’ prior negative experience with that firm. In simple terms, users who were dissatisfied with the firm’s service in the past became more loyal after recommending it. They rationalised it backwards, “If I recommended the company, then they offer a good service” (change of attitude despite prior negative experience).

(Note that this study was not conducted on a group of 120 undergraduates in a non-real life setting, so whether the same impact can be produced in real life remains an open question, but theoretically yes, it can be.)

To reward or not to reward? Re-considered.

Oddly enough, the 2013 study examining churn has also found that the larger the reward offered for referring a customer, the stronger the effect on attitudinal loyalty. How can this be the case? Haven’t we previously said that rewards are bad for making a person committed to their previous action?

The devil is in the detail.

Based on research, it seems that rewards might have a negative impact when you are working with people who have no pre-existing attitude towards your brand or had a negative experience with your brand. In that case, they would be more likely to justify their actions in terms of extrinsic rewards they received.

However, according to positive reinforcement theory when customers already have a positive attitude towards the brand (remember, people participating in referral programs are likely to be existing customers; why would they recommend something to a friend if they did not like it?), a larger reward can strengthen that attitude. So, whether to offer rewards or not would depend on the situation you are dealing with.

Let me reiterate. When you need to create a positive attitude or reverse an existing negative attitude, you should avoid using rewards (if using, the smaller the better). When you need to strengthen an existing positive attitude, rewards can serve you well (the larger the better). At least that’s what these findings suggest.

The how-to of building a commitment through a referral program

When it comes to execution, all the same principles apply. For greatest results, a referral needs to be an active, effortful, public commitment that does not feel coerced.

A referral program used by Typeform ticks all those boxes. It’s important to point out that in contrast to many other referral programs, it allows you to customise the message that will be sent out. Most referral programs just ask you to enter your friends’ email addresses. This is great in terms of simplicity, but you might be missing out on an opportunity to strengthen loyalty of your existing users.

By allowing them to change the message, you create a situation where

1) if they did not change it, that still means that they agree with what is being said (= more active commitment)

2) if they do change the text (telling about their positive experiences), you are building an even stronger commitment because then it also becomes more effortful.

Are you right on time?

Finally, timing is crucial. The 2013 study found that effect was the strongest for customers with low expertise in the service category and little experience with the provider. This means that engaging customers in the referral program at an early stage of the onboarding process would produce maximum effect on their loyalty.


The same principle is at work when customers are voluntarily leaving testimonials. Each testimonial is a public, declarative statement about their experience with your brand. If it was positive, then your customers are likely to use it as a frame of reference when thinking about which brand they prefer.

Basecamp shows testimonials of 1,000 of its customers on their website.

Each is an active, public, effortful statement about their experience that was not coerced.

Key takeaways

I explored the commitment & consistency principle with all of its peculiar subtleties. It appears that its application is not as simple as breaking a larger request into a series of smaller ones. For it to take a substantial, lasting effect, the first commitment needs to establish (or reinforce) a certain self-image within a person.

That self-image would act as a frame of reference for a person to decide whether to commit to subsequent requests or not.

For maximum chances of establishing a desirable self-image, the first commitment needs to be:

To enhance the likelihood of inserting that self-image, you can:

To make sure the process goes smoothly, think about how the principle of commitment & consistency interacts with other principles of influence:

If planning to use rewards:

As we have seen, this principle can be successfully applied to improve email signups, user onboarding, check-out funnels and lead generation. More importantly it can strengthen loyalty of your newly acquired customers (for example, through referral or testimonial programs).

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