The bulk of your income will come from the various lobbies, so it's important to devote a lot of attention to them. You need to unlock new ones on a regular basis, but you also need to improve the ones already available. The bests strategy is to stick with whatever effort you can take most conveniently, rather than saving up for the ones that are more difficult to obtain. Even less impressive lobbies can quickly become useful if you're ranking them up and the speed with which they produce income is steadily improving.