There was one where you could put things like Subscribe to youtube make them watch the whole video and everything. I used to use it for ranking YouTube.I only know about Amazon's mechanical turk (mturk.com), but I'm not sure that it has what you're asking...
If you have the patience to go through all of these sites look up stuff like "micro jobs sites", or "microworkers", or "crowdsourcing sites", etc in google and you'll find dozens of them
I don't know, man, I never used such services... But I'm pretty sure that a lot of crowdsourcing sites can do that thing nowadays... or at least the big ones. Seriously, spend 10-20 minutes to go through each one that you find (or at least the 5-10 ones that come up the most) and you'll find it, they're all clones of each other anyway, if one of them doesn't offer a service that others do it will be left behind usually, so they're bound to offer the same things
sproutworkers
He's right and their is so much more websites that you can find, just depends on exactly what you need.
