I've used it lots of ways.

transcription of audio interviews, paid 8 bucks

help me brainstorm a problem while I was flying from city to city for work, they did a good job on that one

validate a hunch we had at the office on some language in a research assignment, basically quick proof, get a taste on whether or not it was connecting with them

many times ive used it to get what i call fuel before a meeting, get a quick read on folks on brand or research aspects of something

i don't use turk in the traditional sense, i see it as a personal army ready to process whatever you got, a survey np, help you think outloud np, research when you cant, np, turk is pretty cool, but it all depends on what you want to get out of it