Nearly every day we receive emails from users asking why we don't have a section for a given program. The answer is usually fairly straight forward (often depressingly straight forward): The people who make program X don't respond to emails from us.
To have a gallery on WinCustomize.com the following criteria have to be met:
(1) The program that uses the content has to be reasonably popular
(2) The people who make the program have to be willing to link to their gallery in a way that will send users here.
(3) The people who make the program whose content we'd be hosting have to agree to help "seed" the gallery to get it going.
That's pretty much it. So if you have a favorite program whose skins you wish we had, contact the authors and ask them to contact us about getting a gallery up for them. WinCustomize.com has 2.1 MILLION registered users and monthly traffic that exceeds 3 million unique visitors, it's a great way to get a program much greater visibility. But in return, we need the program authors to send us traffic too.