One of the most well known findings in the psychology of marketing and persuasion is the “foot-in-the-door” effect. In its original and most famous demonstration, Jonathan Freedman and Scott Fraser went to homeowners in Palo Alto and asked them if they would be willing to put up a large, ugly sign in their front yards that said “Drive Carefully.” Only 17% were willing to put up such a sign.

However, for a second group of houses, Freedman and Fraser tried something more subtle. The homeowners were simply asked to place a small, 3 inch sign in their windows advocating safe driving, a request designed to be so innocuous that nearly everyone would agree to it. Two weeks later, a different person showed up at these same homes and asked if they would they be willing to put up the large, ugly sign. This time, 76% of homeowners agreed to put it up!

As the name “foot-in-the-door” implies, this effect occurs when customers have done something small for you, which leads them to be more willing to do something bigger for you later on. It is also a well known and widely used tactic in everything from auto sales to telemarketing (where it dramatically increases people’s likelihood to stay on the phone). However, using it in an online context has some unique challenges, so in this post I will outline some ways to effectively get an online foot-in-the-door.

Commitment and Consistency

There are a lot of factors that can drive the foot-in-the-door phenomenon depending on context, but at its core is an idea that calls “commitment and consistency.” Essentially, a homeowner or customer’s first action serves as a point of commitment to a behavior or attitude. When it is time to make the second decision (e.g. to place a large sign on your lawn or to purchase something online), the fact that your customer has already committed (even in a costless way) to the first action leads them to feel a need to be consistent with that commitment.

An important consequence of this mechanism is that the first action must be voluntary: if a customer is forced to do something, it will not serve as a foot-in-the-door because they do not feel a need to be consistent with it.

Naturally a number of other factors will affect the strength of foot-in-the-door as well. For example, if the first action is more public or visible, if it was more personally relevant, or if was expensive (in money, time, etc), customers will be more likely to commit to it.

If I Did it I’ll Do it Again

Because past behavior is such a strong first step for a foot-in-the-door effect, anything that draws customers’ attention to relevant past actions has the potential to open the door. One of the most obvious implications is that reminding returning customers of their previous purchases can be very powerful. This can come in a couple of forms.

One example would be a sidebar that shows either a list or a tally of previous purchases. This feature could be designed to “help customers keep track of past purchases” or to encourage them to rate products, but it would also serve to reinforce their relationship with your website as a place where they go to buy things. “I’ve bought these things from here before, so I must trust the site enough to buy again.” (Potentially, such a sidebar could even be designed to gamify how customers add new purchases to the list.)

A second approach would be to strengthen the message accompanying a recommendation engine. To use examples from Amazon, recommendations ought to use fewer messages like “Recommended for you” and more messages like “Customers who bought this item also bought.” General recommendation pages may also evoke specific past purchases: “If you liked X, then you’ll also like Y.”

Another approach might be to entice a customer to add something to their cart in order to jump-start their willingness to shop. For example, when a customer arrives on the site, they may be greeted with a message and a choice: “Welcome to our website! Please choose a free gift…” This approach not only encourages customers to engage with a product and with their cart, but it also leverages reciprocity.

Ask Me Anything

It is also important to note that the foot-in-the-door effect is not limited to behaviors that are similar to the behavior you are hoping to create. In the Freedman and Fraser study, while they found that asking for similar behaviors (i.e. agreeing to a small sign and to a big sign) produced a 76% compliance rate, they also found that asking for an initial behavior that was not the same (i.e. signing a petition or agreeing to a small sign that advocated a different cause) still led to a 48% compliance rate.

This suggests that a foot-in-the-door effect can be created by prompting visitors for input other than purchases. For example, simple and costless calls to action can lead your customer to start engaging with your site, which may serve as a foot-in-the-door for engaging with the products. Just ask them a question or prompt them to click on something, just try to make it risk free, fun, and maybe a little meaningful. For example, asking your customers about their preferences (like Netflix does for new accounts) might serve as a valuable way to get a recommendation engine started (or to design messages for customers with no purchase histories: “If you like action movies, then you will like…”), but getting them to tell you what they like (or want) may also serve to get a foot-in-the-door.

Conversions Aren’t Everything

Up to this point, the focus of this post has been on encouraging purchasing behavior by first getting customers to do something with your site, but the foot-in-the-door effect is perhaps even better suited to encouraging relatively more costless behaviors. For example, if you have a mailing list that you want visitors to join or a source of content marketing you want them to view, prompt them with a simple pop-up or banner question. If they respond (or when they respond depending on how you set it up), prompt them to sign-up or follow a link with the understanding that doing so would be consistent with the opinion they just expressed. The content-sharing site Upworthy had implemented pop-ups that did exactly this:

Takeaways

1. Get customers to voluntarily do something small for you in order to make them more likely to do something big for you later.
2. Get them to express their opinions, values, or preferences (either by asking or by observing), and then remind them of these as they shop.

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