As far as actually believing in them, I generally don't. But with all of that being said, sometimes getting your fortune told is fun. Even if it is so broadly worded that it's sure to be true, sometimes you just need that feeling you get from it when you personalize such a broad statement to yourself.
Sometimes you just need that 'good' fortune to emotionally pick you up out of the gutter or remind you to do something that you need to do in life anyways. A good number of horoscopes tend to tell you what you could be doing that day.
With all of that being said, I don't see any harm from fortune telling. It gives some people hope that they can't find elsewhere. It gives them a reason not to throw their hands up and say "I give up" on something.
Personally, I occasionally read the horoscopes, if only to entertain myself with the possibilities for the moment before I think, "LMAO, this is all BS."