What would be the difference with the paid version vs. the free version? Would you have any monitoring tools over your server with the free version or only be able to view the player list? And of course go to the websites.
Personally I don't think I'd want to restrict users from better features by making them pay for it to get them, but I have yet to decide the difference between the free and paid version. It will definitely not contain any ads.
Another feature I was thinking of was something I'd call "Blockland Sync"
On the go, you can browse RTB addons and if you find a neat one, you can download it and it'll send it to your computer for you to use when you get back :O
You'd have to download a program on the computer for this to happen though. Thoughts?