Welcome to Negative World. If you have any question, please read the following list and click to read an answer. If your question isn't in the list or if you have a suggestion, feel free to post a reply.
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Currently, the site doesn't bring in much money, and it costs about $85 a year to keep up. Not a whole lot, but the owner of this site isn't particularly rich, so every bit helps. Also, the web designer spent a lot of time and work to implement skins, navigation layout, make the site work quick and neat, and implement the options you asked him, all this instead of doing a paid professional site. The more you support the site, the better it'll run and the more potential its future will have.
I don't even fully know why there is such a hard limit, I really can't remember. But you got it done, one way or another! As for a different number of top 10, I thought about it but I never got around to programming it. It'd probably be a bit of a project really, that 10 limit is baked into a lot of code / images / etc. I think.