Otone, this is from the last Sirius 10-K report filed on 2/29/08:
"On February 27, 2008, there were approximately 850,000 beneficial holders of our common stock."
From XM's last 10-K filed on 2/28/08, it says this:
"As of January 31, 2008, there were 3,668 holders of record of our Class A common stock."
Yes there is a huge disparity between the two, but note the different language. Sirius is using the overall beneficial holders -- while XM is using just the number of Street holders. Which means, if you have shares through Etrade and there were 10,000 accounts on Etrade that held XM shares -- then XM would count them as 1 holder, being Etrade.
I asked about the difference at an XM stockholder meeting and was told that yes, there are just a couple thousand street-named holders of XM -- but there are (or were) about 70,000 copies of the proxy printed up, as ordered by the various brokerages. That was in 2005 when the number of street named holders was around 1,700. Now that there are 3,668 holders of record, it is probably closer to 150,000 beneficial holders of XM, or were just prior to the merger.
When you combine the XM holders with the Sirius holders, you can see how there are close to (if not more than) 1 million beneficial holders of Sirius.
I know it's hard to believe -- but back in 2004/5, Sirius made a big deal out of the fact that Sirius was so widely held, while XM had just a fraction of the number of holders. They made a huge deal out of it in fact -- Joe Clayton was elated over it.