Post-it notes can be mighty persuasive, according to a study by psychology professor Randy Garner at Sam Houston University in Texas. For the study, participants were asked to fill out a survey. Some of the packets handed out to the participants had a note handwritten on the cover of the survey, and some packets had Post-it notes with a handwritten note. Garner found that participants were more likely to comply and f ll out the survey if there was a handwritten note on a Post-it.

Not only that, but participants also returned the materials more promptly and they gave higher-quality responses. A more personalized Post-it increased returns when the survey was more complex, but was no more effective than a non-personalized Post-it when the survey was a simple task to accomplish.

The research points to the conclusion that requests made on Post-its are interpreted as a request for a personal favor, and people are therefore more likely to comply with requests written on them, even if the person making the request is a stranger.