I find more and more porn sites as referrers in my stats. It always looks like this: www.somepornsite.com/00000022.html If I visit the page I'm redirected to their homepage. Are they doing this in hope I put my stats online and they get a back link? Or do they hope they'll get me (any webmaster) as a customer? Do they have other reasons?
Pornsites referrer spam for a couple reasons. One, your site may post the top 'referrers' publically, two to waste your bandwidth, three, to post comments to a possible blog. they're evil and you may look into an application called Bad Behavior, it's a bot-blocking tool which has proven to be most effective against all bots.