There's be something that I've always kind of wanted, for various reasons over time, and that's to get like a "sales report" upon logging in. Basically it could be the same message you get when someone buys stuff from you while you're online, just anything sold while you were offline gets "told" to you when you log in.
I've never suggested it before because although I'm sure there will be a mix of players who thing that this will just be useless spam (adding an option to turn this off could eliminate that) to those who greatly agree with me for the very reason I'm about to state.
--edited--
***EDIT*** And as an update, 4 additional level 5 discs were put up and the SAME person bought them up.