I think that the biggets problem Big Ambitions is going to face, is how to keep the player engaged in the game over a long period of time. I see quite a few people figuring out how to “min-max” the game and finding themselves bored and without any goals.
I believe the key to this problem is to create a robust system where the player competes with other businesses and through the competition you create “a story” of overcoming difficult circumstances/ odds.
What is needed for this to work
You need an easy way to see who you compete with in the district your business is located and how well they score on the given competitive parameters. They need to be simulated (play by the same rules as the player), so that your actions affect them and vice-versa. And with well implemented random events (not too serious, nor too frequent) this could create a relatively fluid system of competition.
Parameters that you can compete in. The four parameters already present in the game (that affects customer satisfaction) would work well, but they need to be made more complex and you would need to be able to compare your stats with your competitors.
Some ways of adding complexity: Sales handling time, sales campaigns (“two for one” - hitting your revenue, but increasing sale and satisfaction), location (where it is located and how it looks and functions indoors), complimentary things for the customer (coffee, cookies, candy) etc.
The employees will be the most important puzzle piece to make this system interesting in the long run. One way of doing so will be to create a system where you have to keep them happy, which in turn helps the way they treat customers and can give you an edge over your competitors: Emplyee personality, vacations, training (courses and eductiona), salary, coffee machine, lunch room, hygiene etc.
These are just my initial thoughts, so please add to them in the comments if you find this to be an interesting idea.