XM Satellite earnings: Is subscriber growth enough?

XM Satellite Radio Holdings Inc. (NASDAQ: XMSR) has announced quarterly earnings this morning with revenue increasing 22% year over year to $277 million. XM's 2007 second quarter net loss narrowed to $176 million, or 57 cents a share, a 23% improvement compared to the 2006 second quarter net loss of $229 million, or 87 cents, in the year-ago period. Excluding charges, the company's earnings per share was 45 cents per share.

Analysts polled by Thomson Financial expected the company to lose 44 cents a share on revenues of $275 million.

XM also ended the quarter with more than 8.25 million subscribers compared to 6.90 million subscribers in the prior year period. In the recent quarter XM added 338,000 net subscribers. While new retail subscribers actually fell 74% to 43,000, customers added through the installation of radios by carmakers rose 28% to 295,000. Churn rate remained roughly the same, but conversion rate increased.

The stock was indicating down 3.6% in premarket trading.

I'll be liveblogging the earnings call at 10:00 a.m. this morning, in hopes to hear more about the merger with competitor Sirius Satellite Radio (NASDAQ: SIRI) and what the company plans to do in case this doesn't pan out.