1. Linear Income
a. Salary: You work so many hours, you're paid so many hours. 
b. Sales: You make so many sales, you're paid so many sales. 
c. Services: You perform so many services, you're paid so many services. 
-When YOU stop; your INCOME stops. 
-To expand your income you must work more hours and/or hire people. 
-Either way, growth is linear too, and you always have to be there.

2. Residual Income
a. Continuing royalties on patents. 
b. Continuing royalties on copyrights or performances. 
c. Payments on renewals of memberships, subscriptions or insurance policies which were originally sold by you. 
-These tend to dwindle over time and finally peter out. 
-To expand your income you must work faster and/or hire people. 
-Either way, growth is only linear, and you always have to be there.

3. Franchise Income
Continuing payments based on gross volume produced by franchises you originally sold as a master franchisor or franchising company owner. 
-Doesn't peter out, but may suffer in recessions. 
-To expand your income you must sell more franchises (growth is linear) or introduce new products (slightly geometric). 
-Either way, you always have to be there.

4. Multiplex Income
Continuing payments based on gross volume produced by franchises which you originally sold as an independent agent, plus franchises they originally sold as independent agents, plus ones they did, and so on, out to a predetermined finite limit. You are both a franchisee and a franchisor. This is Network Marketing. 
-In consumables this tends to keep growing even in recessions. 
-Once you find your key people, growth can become wildly geometric, explosive, even exponential .....and you don't always have to be there.