Mankie, XM doesn't have sponsored programs like "brought to you by" anywhere. The commercial free channels are commercial free.
If you buy a newspaper or a magazine or cable TV, you are definitely "paying for ads." Relative to other media, the ads on XM are symbolic. Believe me, after the crap radio you've become accustomed to, it is difficult to imagine just how ad-free XM really is. They're not stupid, they know nobody will pay for the same crap that's on the air right now.
Also, I beg to differ about the depth of selection on XM v. that of your CD collection. It couldn't be more opposite than you imagine. As I'm sure Paige would confirm for you, XM is committed to having every single CD ever released in its system, and I believe they're up to something like 25 or 30 terrabytes -- well over 2 million songs in their library not including a big room full of CDs. Whatever obscure request you can imagine, they will probably play it for you in very short order. (Also unlike crap FM).
With your CDs you are already familiar with everything. XM does what radio may once have done a long time ago, and is supposed to do: it introduces you to new music. Because the selection is so vast, there is very little repetition, except for maybe 20 on 20, which is designed to play the top 20 as voted on constantly.
I have definitely been buying fewer CDs since getting XM, but the ones I do buy are usually things I've heard on XM that I would not have necessarily heard anywhere else without some serious internet exploration (my previous way of learning about new music).
Finally, as for catching the bottom in the stock before it shot back up, that's a tricky thing to do. Most people who aren't glued to the screen and don't have a feel for technical analysis aren't going to pick such sweet spots. The absurd selloff did confirm very solid support at 10, a previous support level from which the stock bounced hard on massive volume. This is as good a time as any to buy.