If you look at my top-voted answers, they all seem like things where someone either doesn't understand a basic concept, doesn't read available documentation, or hits an error message and drops it directly into Google without considering the issue on their own. It's an interesting phenomenon, and I wonder if it's a observation for other users. I have really simple questions that still get me 1-2 upvotes a month for years after the answer was provided.

If the answer also happens to be for a popular language/framework/n00b problem, then all the better.

Ex: http://stackoverflow.com/users/249543/jefflunt

If this is common, then it would seem a reasonable strategy to just look for easy questions and answer them quickly - if the only reason you're on SO is to play the reputation game, that is.

This supports my general view that, if you want a decent chance at running a business that will have a large client base, simply take a problem that is very common, but not very difficult (maybe trivial) to solve for an experienced person, and sell an automated solution to the masses.