Thanks for your comment Digital_Quartz.
For some games it might be possible to move substantial logic on the server. These may be: 1) games where there are no strict lag requirements (e.g. adventure games, puzzle games like Puzzle Pirates); 2) games where the needed bandwidth for each client is small and the client does some prediction and/or interpolation.
It is true that you have the additional cost of the server (which would need a lot of bandwidth _and_ computational power); but this cost might be more than compensated by the additional income due to less "piracy". (Or it might not.)
UNIX was half a billion (500000000) seconds old on Tue Nov 5 00:53:20 1985 GMT (measuring since the time(2) epoch). -- Andy Tannenbaum