Check out clickbank, got to "promote products" and you can see there what sells at the moment and how big commission will you get, for seo tools it is usually between 50% and 75% so i guess it is quite high.
Try our SEO ebook affiliate program - commissions are 40% per sale paid to affiliates each month. Payments are guaranteed too by the card processor. Signup Support Product Details
http://lowstressincome.com/r/sub/homework62/ take a look at what they sell, you might find something you like
You can look at our affiliate program for Article Distribution services http://www.articletrader.com/affiliates/ We offer lifetime commissions, and up to $52/sale. You can even earn just by showing our Article RSS feeds.
Email auto-responders pay quite well, some offering residuals on a monthly basis. Webmaster related would also be web hosting, ton of them out there, need to spend some time searching out these ones. Voip is hot, webmasters use voip and the Internet to call their clients nationwide for a low monthly fee. Good paying voip programs: Vonage (CJ), SunRocket (LS), ZingoTel (SAS) and a host of others.
We signed up for your program, though unfortunately something is broken - we never were able to get linking code, nor assign commissions to a name, an address, etc. - it only redirects to a forum.
You must first register at our site, and then sign up for the affiliate program here: http://www.articletrader.com/partner/
Also you can check Regnow. You can select the seo software you like to resell as well as other software products.