Time Warner’s HBO, Cinemax Join Comcast Broadband Trial; Showtime May Take Part

Add HBO and Cinemax to the list of networks taking part in the Comcast (NSDQ: CMCSA) Online On Demand national trial slated to start later this month. The Time Warner (NYSE: TWX) premium networks will start by providing up to 750 hours of programming a month to trial participants who are customers already; they join TW’s Turner Broadcasting as launch participants.

HBO already has been part of a similar multi-platform experiment with former sibling Time Warner Cable; this will be its first national trial. The most surprising aspect is that its involvement wasn’t announced last month when TW CEO Jeff Bewkes and Comcast CEO Brian Roberts teamed up to talk up TV Everywhere and Comcast’s trial. Bewkes, the TV Everywhere cheerleader in chief, comes from HBO and uses the premium network as an example of the value of offering the same programming across different platforms without charging more.

Starz Entertainment was the first premium net to join the trial, bring 300 movies and some original programming. So far, Showtime is the odd man out when it comes to premium networks. A spokesman says the CBS (NYSE: CBS) network is looking at taking part but my understanding is that discussions aren’t close to done.

Keep in mind, all of this fuss is over a very small trial in the scheme of things — roughly 5,000 Comcast subscribers across the country — and that these deals are not long-term agreements that would cover a full roll out. The trial, which will make programming available through Comcast.net and the company’s video portal Fancast.com, is primarily a way to test the technology while providing a sampling of info for advertisers and programmers. Expect a flurry of announcements as other networks formalize their involvement or agree to take part. In addition to Turner’s TNT and TBS, Starz, HBO and Cinemax, known participants include AETN, Scripps Networks (NYSE: SNI) and Rainbow Networks.