Despite anecdotal evidence to suggest that Big Brother: After Dark has been a boon to Showtime’s once obscure sister channel ShoToo, the pay cabler won’t release ratings for the show that features nightly video from CBS’ Big Brother house. Up until this summer, ShoToo was an also-ran channel in the Showtime family that aired movies and reruns of Showtime series. Once it started airing nightly video from the house in July, however, ShoToo became the talk of the blogosphere and among BB fans who appreciated watching the feeds on TV rather than from their computer monitors (video from the house is available online from Real Player). Even BB insiders have hinted that After Dark has significantly boosted ShoToo’s visibility and are even considering whether to have ShoToo extend After Dark’s nightly run next summer.

Unfortunately, a Showtime spokesman explained that Nielsen doesn’t allow it to release After Dark’s ratings – but then a Nielsen spokeswoman countered that Showtime doesn’t allow it to release the ratings. Oookay… so that makes a lot of sense. Maybe Showtime’s just gun-shy about touting ratings for a show that it didn’t produce in the first place? Whatever. We’ll tune in next summer if After Dark is back. The final episode of Big Brother, meanwhile, airs Sept. 18 on CBS.