It depends on the value of the question. We get a million love and relationship questions around here because of the girls worrying about when to blow their bfs and whatnot. Thus those aren't worth much at all. The highest categories are Beauty & Style and Home & Garden I believe, but don't quote me on that. In essence, the more thought provoking the category or the less common it is, the more points it's worth. It's just based on the category something fits in.
The commercial value of the category determines how many pionts that category is worth...sorry, I can't believe this didn't get answered already.
lol, thanks, i think someone already gave me the answer somewhere else... (the price of knowing too many advisors :))