silly question?

[Kangamama]

I was just wondering if anyone knows why you can't purchase cd supplies in mainstream stores. I know you can get gerber prefolds and plastic pants but that's pretty basic. We knew we wanted to cd from the start and started out with these items. We had done a little research online but obviously not enough because as much as we're willing and happy to continue cding as we have been I am learning that there are so many other options. DH thinks that perhaps the reason mainstream stores don't sell these items is because there isn't enough of a market but I find this hard to believe!