Every second of the day, a wealth of data stream from a global maze of social networks, smartphones, point-of-sale devices, medical records, financial transactions, automobiles, energy meters, and other digital sources. Such big data, fueled largely by personal data about all of us, represent an asset class every bit as valuable as gold or oil.

In fact, freely flowing data-infinitely generated, distributed, mined, combined, tracked, and connected-play a particularly critical role in many of the products and services that make up the Internet economy. According to The Boston Consulting Group's research, by 2016 the Internet economy will reach $4.2 trillion in value in the developed markets of the G-20, or 5.3 percent of their GDP. In these countries, the Internet economy is growing at 8 percent annually, far outpacing just about every traditional sector in many otherwise-struggling economies-and growth rates are more than twice as fast in developing markets.

Consumers are the real beneficiaries of the Internet economy. The value they place on the many Internet services that have been built atop the sharing of personal data-such as search engines, e-mail, news sites, and social-network services-reflects that benefit. Consumers value the Internet at many times more than its cost, BCG has found.