A classic and popular misconception that "no one in their right mind would do this", yet they do. The time for effort formula trips up a lot of people, your not the first one come up with this analysis.
The problem you have is the lens you're looking through. No one paid you to post here, no one paid you to participate in a social network, watch a youtube video, let alone make a blog, yet a whole heck of alot of the folks on the planet do it.
People need to stop looking at turk through the "job" lens because it will never ever make sense. But if you look at it through the multitasking, social media, bored outa my gord, what the hell, yearning to participate in something, be apart of something, advisory and authority lens it makes much more sense.
Meanwhile, read up on turks, get to know their behaviors and find out the why behind their actions.
http://www.floozyspeak.com/blog/archives/2008/08/valley_of_t...
Don't take my word for it, go ask them yourself, make HIT, put it up there and see for yourself. But take the traditional "this is a job" lens off cause that is a classic misguided view of mechanical turk.