There are exceptions to every rule, but here are some basic guidelines. The product should have mass appeal.
Television is a broadcast medium.
Niche products tend to not do well. Ideally, there will be a wide range of demographics interested in your product. For instance, a product that makes you look better, younger, or thinner. Also, any products that will save a consumer substantial time or money will do well. Demonstrate Products that are easy to demonstrate on television do very well.