Researcher Randy Garner wanted to know whether simply affixing Post-It Notes with handwritten instructions could increase the percentage of people who returned surveys.
In his study, Garner used three conditions: 1) a group who received surveys with additional instructions typed in a cover letter; 2) a group who received additional instructions on a handwritten cover letter; and 3) a group who received additional instructions handwritten on a post-it note. 36% of typed-letter group returned the surveys; 48% of the handwritten-letter group returned the surveys; and 75% of the Post-It Note group returned the surveys, making the Post-It Notes much more effective than even the handwritten cover letter.
To make sure it was not just the jazzy neon color of the post-its encouraging survey takers, Garner did a follow-up study and sent out surveys with handwritten notes on post-its, post-its that were blank, surveys with no note at all. The post-its with handwritten notes again proved most effective.
The benefit is likely from a combination of the catchy color and the handwritten note.
But why would survey takers care if someone spent 30 seconds scrawling a note on a post-it? It's something persuasion researchers call reciprocity.
When someone does something nice for us, we like to repay that kindness. The handwritten notes are evidence of the researchers having taken time to personally explain the process to each survey taker. It would seem rude not to acknowledge their efforts by completing the survey.
So next time you have a document or report that requires attention, write a personal note on a sticky note. Bonus points if you say "thank you" and sign your name.