It's nothing really. The only thing it does is how much rep points you can give (or subtract) from another poster. The more rep points you have, the more points you can give or take to other posters. And People just ask for them because they like seeing a lot of green squares by their rep. I know I do.
^^^I'll take away from yours if you make another spam post like that. You haven't really got the warning points to be playing around with, and negative rep from me would substantially lower what you have at the moment.