I'm actually getting some good traffic out of Google and other SEs. No sales yet (unfortunately), but considering how long my site has been around (a few weeks) it's encouraging to see the amount of traffic coming in from them. SEO really isn't as much as a pain in the ass as everyone makes it out to be. There are just two things you need to really pay attention to when building a website: character encoding (iso-8859-1 in my case) and doctype (XHTML 1.0 Transitional in my case). Make sure your site at validator.w3.org (e.g.
http://validator.w3.org/check?uri=www.adultpicweb.com) and the search engines will be more than happy to index your site. Unfortunately, exactly how long your site will remain at the top of any heap in terms of results is extermely unpredictable (I've seen my site be at the top of some results for a little while then just disappear).
Traffic trading is where the majority of my traffic seems to come from though, but its extremely painful though as some people seem to try and yank my chain with hit bots and other crap. I currently have my system set to obey findtrades, but I really am starting to think about making it exclusive to find trades. Note: if you're looking into traffic trading backends I'm actually thinking of not recommending ePower Trader (I'm actually thinking of replacing it) because some of the numbers that it's giving me and some of behavior it's reporting make no sense.
RSS also does seem to be yielding a lot of return traffic for me so that's something to think about.