Collecting Friends

With the recent explosion of social networking sites, something has always puzzled me. First, consider this excerpt from Robert Scoble’s blog:

“Twitter is still ahead, but growing far slower. Just today I added another 120 friends to Pownce for a total of 839. More than 4,400 on Twitter and more than 1,200 on Facebook.”

My question is this: Is there any value actually garnered from adding an obscenely large amount of random people as your friend on various social sites?

Honestly, if a social networking site it meant to enhance you life through discovery of new interests, music, recommendations, etc…, is that easily done by wading through thousands of people?

At what point does the quality of a social connection come into play and if you have thousands of social connections, how can you possibly assess the quality of those connections?