Paydotcom is actually another affiliate network something like Clickbank. They mainly deal with online electronics products. You can actually input your clickbank iD and start putting a cute little widget (PayDotCom Widget) on your site or blog. If anyone click on the widget link, directed to merchant site and makes a sale, you earn commission just as usual affiliate marketing. Sign up with PayDotCom now and Start earning money online with it.

To sum it up, you basically get 3 benefit.

1. Get the widget to put clickbank product on your site with affiliate link in it.
2. Get access to a huge marketplace of products and earn commission(like Clickbank)
3. You can promote PayDotCom itself to earn money.
4. You can sell and promote your own product on it too. (again like clickbank but in a more user friendly manner)