I was going to write this, but it was done so well by Kat French over at Social Media Explorer, that I'll just send you over there.  A taste.

SEOs complain that bloggers, social news power users and other social media types are pimping the system in their own way, and are often woefully uninformed about the basics of how search engines index and rank sites.

On the other hand, I also see a lot of cross-pollination of ideas among the top players on both sides.

The fact is, search and social are, if you’ll pardon the pun, intrinsically linked. As long as Google dominates search (which all evidence points to being for the foreseeable future), developing quality inbound links will be invaluable in search engine optimization.