I've been with Wincustomize since 3/25/2001 and I'm member number 261.
For those who still don't know the story, at the end of the year 2000 Wincustomize still did not exist and Skinz.org was *the* place to be, as Customize.org had been before that. Windows customization was still very much a niche market and the dot.com bubble had just burst.
Skinz.org was owned by eFront, an advertising network run by a shady character named Sam Jain, who 'invested' in popular web sites in return for the right to host eFront banner ads in them *and* ownership of the sites themselves (bandwidth was very, very, expensive in those days, and many free web sites fell victim of their own success, so it was either that or submit to someone like Sam Jain - i.e.; essentially selling your soul to the devil).
As the dot.com bubble burst, eFront was unable to make payments to the various web sites due to lack of advertising revenue. This created a major war with affiliates, and, at one point, someone leaked the ICQ logs (remember that messaging application?) of Sam Jain's conversations with employees and other people. This put bare all the shady practices performed by eFront and Sam Jain himself, such as not paying affiliates, sending legal threats to anyone who spoke badly of eFront, etc... The release of the logs paralyzed eFront (several key employees resigned) and created a personal nightmare for Jain, who would later run into trouble with the law due to unrelated matters.
Anyway, now unable to meet their financial compromises, Skinz.org was dying. Webmasters at Skinz.org (remember Shoggot?) were not getting paid, and, in addition, many skinners had removed their works from it in protest of Skinz.org affiliation to eFront.
It was at this point that Brad Wardel and Stardock stepped up with the creation of Wincustomize to fill the void. It was a *very risky* move back then, because, as I mentioned, bandwidth was terribly expensive (nothing like a skins site to gobble up TONS of bandwidth, which would then have to be paid by revenue taken from the sales of Stardock applications) and Stardock was nowhere near as big as it is these days.
Furthermore, with many different customizable applications existing back then, many skinners were very weary of adopting Wincustomize as their 'new home' because it was backed by Stardock, a maker of commercial (boohooo, evil, ehehe ) skinnable applications set on dominating the market. Brad counteracted this by opening up Wincustomize to non-Stardock skinnable applications from the very beginning - and, in part thanks to this, Wincustomize succeeded in taking the place of Skinz.org (which is now a ghost town, as are most of the other skin sites of the time - except for DeviantArt, which grew in a different direction).
If you ever wondered why there is a Winstep section here at Wincustomize, even though Winstep and Stardock are 'competitors' (note the brackets), now you know why.