They often feature celebrities, but they aren't regular TV shows. Infomercials are simply a new type of TV commercial. They look real because they copy the format of TV entertainment shows. In reality, they are simply paid advertisements featuring compensated actors endorsing products or services. Look for commercials during the show promoting the same product discussed in the show.
Infomercials often feature a toll free number or ordering information on the screen during the show.
Remember, they are trying to sell a product. They want to make sure that you know how to order the product. FCC rules require a sponsor of a paid program to disclose who is paying for the program at either the beginning or end of the infomercial. Infomercials sell a wide variety of products. Infomercials often feature endorsements by celebrities who were once popular.