It is a way to measure your interaction with/in the site.

Yes you will fid people making comments jut to earn soe points, but in the end it s not a matter of quantity but about quality.

And also besides points you might get some nice "THANKS" from te people asking question or looking for sugestions, and to which you gave responses.

Regards!!!

PS: If you need additional explanation please refer to the search option....this topic has been dealed in the forums for several times now.