Places That Work For Real Web Traffic And Sales?

Its really hard to find sites that actually work for promoting a website. I’m looking for answers that will tell me from experience of sites that sell advertising or links that really produce results. I sell software (SEO) and so far I have found, when it comes to actually making the sales the best places are eBay, Adbrite, Overture, and Adwords. Outside of that I can’t find anything else that works. Any suggestions from personal experience?