Advertising has already given us an abundance of free services -- e-mail, instant messaging, search, news, storage and countless Web sites, not to mention broadcast television, radio, newspapers and magazines. It has also financed the growth of two of the IT industry's most important and influential companies, Google and Yahoo.

While thus far most free services have been targeted at individual consumers, there is now growing interest in testing whether advertising-based models can be applied to enterprise IT markets. It's one of our industry's upcoming megaquestions.

For many decades, advertisers have tried to reach people in the workplace. The workforce constitutes a larger and more representative set of adults than those who watch TV or read newspapers. While business publications partially fulfill this demand, their reach is limited, and real-time targeting is generally not possible. Internet technologies can provide powerful solutions to these challenges and are theoretically capable of funding a wide range of software and service offerings at the companies that choose to provide data for advertising programs.

There is potentially a great deal of money available. According to the Interactive Advertising Bureau, total U.S. online advertising spending reached some US$12 billion in 2005. But this is just 4 percent of the total U.S. advertising market. Given the impressive content and services that $12 billion has already financed, imagine what the Internet industry might do with $50 billion or even $100 billion. If advertising can pay for activities as complex as the Olympics, why can't it support basic enterprise applications and services?

To get a sense of how this might work someday, consider the following: Would your company be interested in, say, a Web-based corporate calendar system that is not only free, but might also actually pay you money? For example, if traveling employees could be automatically targeted with ads for nearby hotels, restaurants, entertainment and office support services in the cities they're visiting, you could be eligible for cash or bonus points based on resulting responses.