Other people
Commitment and consistency (foot in the door)
People who agree to a small request are more likely to agree to a larger one later.
ContestedReplications or meta-analyses disagree. Do not assume the effect.
Example
Households that first agreed to a small sticker were more likely to later accept a large sign in their yard.
Why it works
Acting once leads people to see themselves as that kind of person and act consistently. Reviews find the effect small and sometimes absent.
On the web
Open a form with an easy question about the visitor’s situation. Put small actions such as "try free" or "save" first.
When it backfires
Stacking small yeses toward a big commitment you never disclosed is deception. Say up front what you will ultimately ask for.
Sources
76% of households that had agreed to a small related request accepted a large sign, compared with 17% asked directly.
Freedman, J. L., & Fraser, S. C. (1966). Compliance without pressure: The foot-in-the-door technique. Journal of Personality and Social Psychology, 4(2), 195-202. Open source
Across studies the effect was small and depended on conditions such as timing and the nature of the requests.
Burger, J. M. (1999). The foot-in-the-door compliance procedure: A multiple-process analysis and review. Personality and Social Psychology Review, 3(4), 303-325. Open source