Post-it persuasion

I recently came across a study that finds that surveys that have a Post-it note attached get better response rates than those that are sent out unadorned. Interesting! I wonder if anyone has used this idea for post-activity surveys, and if so, if it really does improve response for longer, more involved surveys (it says there isn't much difference for short and easy ones).

(Thanks to the MeCo Google Group for the pointer.)