PHILADELPHIA (AP) -- Seventeen more cable TV networks said Tuesday they are joining an online video trial by Comcast Corp., a move that tacitly acknowledges advertising isn't enough to support shows streamed over the Internet.
The networks join a growing roster of content providers - including CBS, HBO, Cinemax, TBS, TNT and Starz - that have agreed to participate in Comcast's test, bringing the total to 23 programmers since the initiative was announced in June.
In coming weeks, Philadelphia-based Comcast will be testing the service, which gives 5,000 subscriber households access to cable TV shows online without an extra fee. The trial will let these subscribers watch hundreds of movies and TV shows that previously could not be streamed over the Internet legally.
No other cable company has tried such a project yet. The test is meant to address a dilemma faced by cable programmers, which increasingly believe ads aren't lucrative enough on their own to support online video - the model that sites like Hulu.com are trying for broadcast shows.
Comcast's pilot project will have ads. But the cable networks in the pilot hope that by offering the video content only to paying subscribers, the networks can maintain the fees they get from pay-TV operators while still meeting consumers' demands for shows on the Internet.
For CBS, which also joined the trial Tuesday, the project provides another outlet on which it can sell online video ads, in addition to its CBS.com and TV.com sites. For now CBS is not sending shows to Hulu, which counts the parent companies of NBC, Fox and ABC as co-owners.
In Comcast's test, subscribers will be asked to log in to Comcast.net and Fancast.com to view the online shows and movies. The content will be streamed online to computers for now, with downloads to mobile devices possible in the future.