One of Tivo's major selling points is, obviously, the ability to skip commercials. The other - the cool beep-boop noise it makes when you use the remote.So given the former, it's puzzling why anyone would be interested in Tivo's latest offering, Product Watch, which offers on-demand ads to its subscribers. Erm, aside from perhaps Super Bowl Sunday, why would anyone plop down on the couch with a beer and some popcorn and say, "Let's watch some Ford ads!"Writes The Wall Street Journal, "TiVo is betting that viewers will use its on-demand ad service to research products or services they are thinking about buying - much as people search the Web for information on potential purchases."How much research can you do with a glorified infomercial?