1/ Everyone gets richer but the rich get richer quicker…
a game of hyper inflation similar to what we have now… more money is gained every day by each player and very little/no money is ever “lost” by players. The rent gained from a property must at some point exceed the cost of the building otherwise there is no incentive to buy the building… from this point on money is being introduced into the economy. thus a new player starting with 3m (or a poor player) has very little chance of ever catching up (*Not just* for the 1m bonus rent every day since you registered and logged on).

2/ Some people get poorer while others get richer
a game where players are at some point eliminated/knocked out. A system where there is a finite amount of money in the game (where the positive chance cards balance the negative chance cards). This means all money that is spent or earnt in the game comes from other players (including rent). The only way new money comes into the economy is through new players (i.e every time a player gains money another player loses an equal amount of money). This will almost certainly lead to players being knocked out (like the board game) and would require far more planning (from the programmers) than the simple game we have currently. A new player in this type of game would always have the average (mean) amount of money of all the players.

both types of game of their advantages and disadvantages and either way people will complain