RMT Advertising System.

[BunnyChain]

Tell filters don't work though - SE already tried that years ago with FFXI and... it worked for... a week. Then the RMT companies worked out how the filter functioned, and developed ways around it (such as substituting letters in the tell that the filter would block, such as replacing 'w' with "@' in web addresses and mentioning that fact in the tell so that prospective buyers would know where to go anyway.)

Funny that the 'other' filter works really well. :b
If it's a configurable one you could just change it, instead of filling up your blacklist.
They did already restrict the amount of friend requests to 5 per day. I didn't see any of those in a long while now, instead of getting about 10 or so per day.
Next step would be to have the option to receive tells from friends only.