I checked with the Stratosphere on their promotion where they refund your slot losses up to $125 during your first 30 minutes after joining their slot club. I'm told you they send you a voucher within two weeks (along with an invitation to stay free at the hotel for two weekday nights). You have up to a year to turn in your voucher so since the convention is earlier next year, it should work even for folks that may not be back in Las Vegas until then.