My drum shop guy said that the reason you see so many C & C kits on shows like CBS This Morning Saturday and Austin City Limits is that they give out free promotional kits to selected artists. I'm not connected to the endorsement world. Has anyone else heard that?
I was a C&C endorser for a bit and I can tell you, they do not give free kits to anyone. (At least not that I have ever heard.) They do give their endorsers discounted prices on gear (as do most drum companies), but I have never heard about free gear being given away by them.
C&C are played by everyone from the drummer from The Shins to Spoon to The Flaming Lips to My Morning Jacket and so on. So, while they are definitely big in the indie music world, they have crossed over to more mainstream bands as well.
I can't speak for all the C&C drummers out there, but I think there are a couple of reasons why they are so popular. First off, they focus on vintage sounding drums. When I was an endorser, I had been playing my vintage Ludwig kit, which I loved. The problem was I had several issues with the hardware (lugs) breaking/gear stripping out on me during shows. I really wanted a kit that had that vintage Ludwig sound, but was more reliable. I didn't have $3000+ for a Ludwig Legacy, so I spoke to my friend - a current C&C endorser - and he recommended that I give his C&C kit a try. I did and I loved the warm, Ludwig-ish sound. The C&C drummers I have spoken with also seem to be drawn to vintage sounding/looking drummers.
The second reason is they came out with inexpensive (relatively, at least) vintage sounding/looking drums - specifically the Player Date I and Player Date II series. These are often the drums you see touring drummers play on tv/YouTube. These drums sound and look like vintage drums, but they are attainable for many drummers. The Player Date I series are VERY tubby sounding! They are some of the warmest (and lowest volume) drums on the market. Those things appeal to many drummers, I guess.