Here's a short introduction to the game, on how to earn coins fairly easily without resorting to cheats or hacks.
2. Upgrade shops to higher levels to increase the Max Price and Usage Fee.
3. Do more Investment Tasks to unlock new types of shoppers. More shoppers equates to more spending in the mall.
4. Shoppers will randomly request for directions to certain facilities, giving you a chance to earn [Fever Stars]. Collecting the stars will contribute to triggering [Fever] mode,which, when activated, will speed up the shoppers' spending and increase the overall earnings of the mall.
5. You can choose to expand your shopping mall to make more space for constructing new and different types of facilities, for example: the arcade, cinema and bar. On top of all these, the game allows you to visit your friends' malls, and tip them while visiting. Hire staffs to give shoppers [Tours] which adds to your earnings when you come back to play at a later game session.
It just takes some time, so learn how to be patient..
And patience will eventually earn you LOTS OF COINS! :D
P.S: Let us know if you have any other tips and tricks to share in the comments below!