It is posted many times on most boards including this board that short play on the last day play is best played without a player card because of the way the ADT algorithym is determined. I agree with all that Ryan posted except for the last day play assumption. Doing this will boost your 'average daily theoretical' (ADT) which is how much you are expected to lose theoretically based on your average bet and hours played. This will not work on the table games, but almost all casinos allow the same rewards account to be 'active' on different slot machines at the same time. Another helpful strategy to boost your comps is if you and your wife are both slot players, just use 1 person's rewards card and both play with it (use whoever is getting better offers to begin with). However if their normal play on a 'gambling day' is 4+ hours and they only log an hour, the algorithm used to determine comp offers will definitely ding them for only playing an hour.
Some people make the mistake on check out day of putting their card in the slot machine or table game and playing for an hour or so before heading home thinking that will boost their comps since they played an additional day. Yes, the strategy you are currently using is the best as far as earning and retaining comp offers.
