True...points are very cool.  But there's more to it than that.  When you mark a good answer as Helpful or as a Solution, you show appreciation to the people who took the time to help you.  You are also helping everyone else in the community, because they will now see your topic as "Solved" in the forums with a green "check" icon next to it.  If someone else has a similar question to yours, they might see your solution and be helped by it too!