this has been discussed before.

see, the problem with this idea is:

Level 50s would be spamming low level areas, which would get incredibly boring. Others really couldn't tell you've gotten these advancement points, etc.

my idea:

Instead of kills, what if at level 50, every 15,000 experience, you gain a skill point, and allow all skills to raise 3 above the current cap of 5(will only go above 5 if youre using points obtained with the 15k exp method).

Although, because nobody can tell a specific players damage in a party, nobody would really know but you.

Just a thought, because stat bonuses would be almost pointless, aside from a few dual spec applications.