To celebrate today's launch of the LinkPlug! Directory Affiliate Program we're knocking 30% off the cost of a "Featured Link" for a short time. There's never been a better time to order. Order now — they're just $7.00! Check out the info here. And for those who own a directory or SEO-related website, this is a particularly good affiliate program. You can put an ad for it directly on your directory. In addition, you can also include your affiliate link in your acceptance email as a way to generate additional revenue — even after you've completed a sale!
Unfortunately, I ahven't used PostAffiliate; however, the iDevAffilate script is pretty solid. And support is excellent. It's pretty robust and has a fairly large community with a couple of solid plugins. I'm pretty happy with it. Feel free to sign up as an affiliate at LinkPlug! to have a look at it (or their website has a proper demo of the Admin panel which is pretty nice).