If you a fan of Role Playing Games (RPGs) like I am, then I strongly suggest you visit:
Now I sell my tokens and Maps on all 4 of the above listed sites, but it is only Roll20 that has every one of my packs. That is simply because I make them for Roll20 first and then if the opportunity presents itself I convert it to one of the other formats.
And that comes down to sales, one weekend sales on Roll20 is the equivalent of 3 months+ on the other three. Plus Roll20 of course is free to uses and allows you to download the tokens and maps once you have purchased them, so you can always use them in the other game systems if you like.