Satellite Radio mentions double in top market Arbitron diaries
According to this summary from Arbitron, the fraction of diarykeepers in the NY and LA MSA who reported listening to Satellite Radio more than doubled from Winter 05 to Winter 06.

In fact, in New York the fraction tripled.
This is, of course, the time before and after Howard Stern’s arrival at Sirius, although that’s not likely to be the only cause.