I've never used Mechanical Turk but from what I hear, each action pays out pennies. I think the world is connected enough to where a person should be able to ask a question and get an immediate answer, no matter the subject. People would surely pay for that, in my opinion.
It could work with some sort of verification process where answering gets you the most money but the person confirming an answer gets paid too, albeit a smaller amount. An answer with 5-10 confirmations gets sent to the user, depending on the difficulty of the question. There could be a ranking system where harder questions cost more money to be answered.
Imagine you're visiting a city and want to ask the hive "what's a good hipster cafe?" or, a problem I recently had, construction workers were making lots of noise early in the morning and I wanted to know if that's legal to disturb the peace that early. Big companies want this kind of task to be handled by AI but I'd much prefer a human element to it (like Ask HN/Quora, only on steroids).