Most businesses consist of more than one type of business model.
Even small, entrepreneurial organizations may be diversified. Consider, for example, your local florist. The owner/entrepreneur can pursue three lines of business.
Retail business: Retail customers buy from the florist infrequently and with no assurance of ever returning. Each customer contributes only a small portion of the florist's annual revenue. This business is a Locust.
Events business: Weddings and bar mitzvahs are events that happen once (or, in the case of weddings, only a very limited number of times). These "events" customers purchase large volumes of flowers (table decorations; a range of items for the wedding party; etc.). The total sales from a particular event may constitute a significant proportion of the florist's annual revenues. This business is a Pig.
Institutional business: Churches and hotels purchase flowers to make their facilities more attractive. The florist must supply fresh flowers on a regular basis and, in the process, remove those that have wilted and become unattractive. The customers' purchases are not necessarily large but they recur. This business is a Chicken.
In practice, a florist may choose to operate a business built upon any combination of these models. She/he may choose to focus on one model, diversify by adding a second, or diversify even more widely by incorporating all three.
In the academic world, diversification is part of a branch of strategy called "corporate strategy." The Harvard Business Review published, in 1999, a special edition: Harvard Business Review on Corporate Strategy (Harvard Business Review Paperback Series)
To learn more about the business model approach to diversification: Chickens and Pigs - The Book
