Affiliate Marketing

I am beginning to grasp the basic concept of this whole blogging universe.  In by doing so, I came across two websites that have a full directory of companies that offer affiliate marketing. I've signed up with both companies (completely free!) and have been accepted for a few companies. 

The first one is Commision Junction and they have companies such as Yves Rocher (LOVE them!), Power Swabs (I used to do customer service with this company), ThermoSpa, and various other companies.

The second one is PepperJam Exchange and they offer companies such as Famous Footwear, Babies "R" Us, etc.

I have not been a member long enough to know how profitably it will be(of course a lot of that is dependent upon traffic to your site, plus people clicking on the links) but I thought, wouldn't hurt, right?