Don't know if Android numbers are helpful to you too (maybe just the contrast will be interesting), but here's my experience in the Android market:
a) 1
b) paid
c) I posted in a dozen message board threads or so where people were looking for such an app, and I've diligently answered every e-mail I get about it.
d) It's been in the Market for about a month and a half, and I've made a little over $2000. Hard to give a per-month answer as I don't know if it will taper off and run out of customers. ;)
If you think you may have the IP address, is there any chance that whatever OS you have running on it will let you discretely log in remotely? Then you can drop some sort of homing beacon on for now so that if the criminal moves (likely, given it's a hotel, of course), you're not SOL.
I've often wondered if we could deal with graffiti in a similar way. Since it usually consists of an "artist's" tag that personally identifies him, let's start appending "has an itty-bitty wee-wee" to tags and see if the broadcast of one's tiny manhood solves the problem. :P