4#nightlifer
Generally, all pay content can be found at the booty, for both The Sims 2 and The Sims 3 game. The files get cleaned of any trackers and such like. I don't quite support the concept (I've donated to paysites before, including PeggyZone), but some people do take it quite seriously.
not the best you've ever had, but you say I'm pretty close ...
Anyway, trackers. Basically, popular sites like The Sims Resource like to keep track of who downloads what from their site exactly, which helps them determine what files are popular (most of the time, they approach the creator by asking them if they would like to change their content into pay content), so they code the custom content you download from that site with trackers.
not the best you've ever had, but you say I'm pretty close ...
Thats not the reason they have trackers. The trackers where added so they could find out who downloaded something and then posted it on another site to share. TSR would download the file, get all the info on who the person who shared it, and then go ban them on TSR. It has nothing to do with the popularity of the item, they just have to look at the download number on the download page.