Last week the tenth episode of the second season on HBO’s True Blood attracted 5.3 million viewers, 20% more people than the previous episode and the best audience HBO has had for any show other than The Sopranos in five years. Looking at the viewership for the first Sunday airing of each episode, True Blood has steadily drawn bigger audiences over the course of its run. Even more impressive is that HBO has drawn this size audience with one-third the distribution of most other cable networks. However, as successful as it is True Blood is still well short of the 11.9 million record audience set by The Sopranos finale in 2007.

The success of True Blood seems to somewhat of a systemic cable summer boon, seen at both HBO and Showtime where primetime ratings are above 20% year to year, and at ad-supported cable whose shows are driving an all-time high for TV viewing. In comparison, TV viewing at the broadcast networks is faltering, perhaps indicating that stronger development should be allocated towards next summer.

Last week the second season of True Blood premiered on HBO, receiving the best audience levels of any show since The Sopranos series finale in June 2007.

It’s difficult to get much audience information on HBO, but I did manage to compile the following list. Nielsen adjusted its ratings measurements of HBO after 2004, so its hard to compare audience levels before that point.

The second season premiere of True Blood is 157% above the first season’s premiere of 1.44 million in 2008. It may be that the HBO series was partly helped by popularity of the Twilight series. It might also be a sign that HBO has the first series hit since the days of Tony Soprano.