It was because of Spoon's encyclopedia type knowledge of this show that we came third in the 2005 Ayacon quiz.
Anyhoo. CCS is I think it's fair to say CLAMP's second successful attempt at creating a license to print money (the first being Rayearth). It's precision made commerical anime, full of merchandisable characters and items. And as well as being a machine made to sell things to young girls, it also has cross-over appeal to fetishists of various forms. Oh CLAMP you money making geniuses! Hitting two streams of revenue!
Don't get me wrong, I'm not dismissing the show for it's commercial aspirations and success, there's plenty of shows that have tried the same thing and failed. CLAMP are great writers not so much for the content of their stories on their own, but because they seemingly are able to understand an audience and write directly for that audience. Often that audience is an audience of CLAMP fans (Tsubasa and xxxHolic being prime examples), but on at least three occasions they've gone after and got distinct types of audiences (CCS, Rayearth, Chobits) that lay outside the normal “CLAMP fan” realm. And in doing so widened their core audience.