When Torchwood: Miracle Day premiered on Starz, the show was getting in the neighborhood of 1.5 million viewers, which was respectable but about the same as Starz' recently-cancelled Camelot. With the second episode, the show dipped to about 1.4 million, and Entertainment Weekly warned that if it dipped much further, "Captain Jack might be immortal, but TV shows are not."
So it's probably bad news that the latest Torchwood episode got only about 917,000 viewers, when you combine its 9 PM and 11 PM airings on Starz. This was actually up about 14 percent from the previous week, so at least the bleeding has stopped. (And it looks as though TV By The Numbers was using lower figures for Torchwood all along, so the overall drop isn't as great as it appears at first.)
Meanwhile, the show's not doing that hot in the U.K., either.
All in all, I wouldn't hold your breath for another helping of Torchwood any time soon.