I use them. You gotta be on Amazon. A lot of people search Amazon for stuff to buy on impulse. If they don't find it or don't stumble upon your product then it's a lost sale. The problem is that Amazon only pays a pathetic 45% of list price, AND recently they've started selling stuff for MORE than list. I have two titles on Amazon that I set at $8.99 list and Amazon is selling them for $9.45 and $10.63!!!! So my advice is DO NOT under price your product or Amazon will just pocket the difference for themselves.
Beware than physical media (CD's, DVD's) will become extinct withing 10 years. Don't expect to sell many DVD's. Manufacture as little as possible.