There is a Patent granted to yahoo that stats that the traffic logs of a website are important

Invented by Arkady Borkovsky, Douglas M. Cook, Jean-Marc Langlois, Tomi Poutanen, and Hongyuan Zha
Assigned to Yahoo
US Patent 7,398,271
Granted July 8, 2008
Filed April 16, 2002


Better Web Crawling:
Usually a search engine crawling program discovers new pages to index by finding links to pages on the pages that they crawl. The crawling program may not easily find sites that don’t have many links pointing to them.
But, pages that show up in log files from ISPs or toolbars could be added to the queue of pages to be crawled by a search engine spider
Pages that don’t have many links to them, but show up frequently in log information may even be promoted for faster processing by a search crawler. So the number of visitors to your site does matter, i've started using WTools Traffic and until now works great for me.

Hope this info helps many members.