You'll find these in the "Business Investments" (the icon that looks like a briefcase). These will increase your money value for each time you swipe the money. You will have to start at the top and buy three tiers of it before moving on to the next one. The list is as follows:
Paper route - achievement
Lemonade Stand
Flower Cart
Coffee Shop
Fast Food Chain
Casino
Cigarette Factory - achievement
Soda Company
Railroad Monopoly
Strip Mine - achievement
Arctic Drilling
Candy Theft Ring
Old Lady Smuggling
Clown College
NSA Collaborator - achievement (after buying all three tiers)