what's the purpose of linking to SE's
 

i seen a few sites with links at the bottom of thei site linking to google & yahoo, etc.. what purpose does this serve, other than as a service to the surfer??? does it really have any extended or added benifits?

if you would send quite a lot of searches through your website, I think, google would reward you for that.

so that other people can have you traffic and dont they deserve some traffic back :D

Dunno, noticed all met art hosted galleries do have it as well

I think the purpose is to get serps for people that type in "google porn", "yahoo porn" etc...

It's like the "revisit" metatag, used to work as a grey hat SEO trick on some SE's but now way outdated.

i dont think SE's work that way..

I think the hope is that if someone clicks the link, the s.e. will see the hit coming from that url and then spider the referring url. I've never seen any evidence that this is true though.