An essence of the offer what to enter npc selling " trading licenses ". That is the player buys the license for the hour, four hours or eight hours. Further within the limits of city puts the goods on sale or purchase, using the license. Further it is disconnected from a server, and the game character remains on trade for time specified in the license. It will raise interest to game, also considerably will unload the Internet channels and as consequence to decrease lags.
P.S. I ask a pardon for my English, but I think an essence of the offer it is clear.