From Social Patterns
Generally used in the context of organizations providing social networking or allied services, monetization refers to a coherent business plan that converts ideas into viable business ventures with a predictable, or at least defined, revenue stream.
For instance, in the dotcom days, a lot of companies talked of 'eyeballs' and 'page hits', with no clear way to make money off these hits or page views. In contrast, most new ventures on the web today are designed with the explicit aim of making money by providing services that users want to see.
Monetization is important from the perspective of sustaining a business enterprise and forms the sole basis of existence of a 'for-profit' business entity.