Waste of time: Asking to fill out surveys and nothing is offered. (or a chance to win some $$ or miles

).
Also a waste of time when one has to follow up when points are offered for doing something and they deny you for a small technicality buried in the many pages of fine print.
I rather fill out credit card applications and get 50-100K bonus per application. I even help others (relatives, coworkers, friends) with the FT links for the giant bonuses. Much better use of my time.

. I also "teach" them how to "fish" (read FT, Milepoint, frugaltravelguy & other blogs

).