Television had Nielsen ratings. The web had a flood of traffic claims and almost no numbers anyone trusted. NetRatings built a panel of internet users, measured their browsing, and sold the results to publishers and advertisers. When it filed to go public in late 1999, online ad spending was soaring. Buyers badly wanted to know who was actually watching, and NetRatings promised to tell them.

Borrowing Nielsen's Name

NetRatings bet that the internet would need an independent ratings service, just as broadcasting had. Advertisers would not move big budgets online without audience numbers they believed. Early on, NetRatings formed a partnership with Nielsen Media Research, which lent its data a name advertisers already trusted. The service became known as Nielsen//NetRatings. Its numbers became a common currency in online advertising.

Bought Back by Nielsen

NetRatings priced at $17 a share in December 1999. After the crash it bought several rivals and research firms as the market consolidated. It stayed one of the standard sources for web audience data, and Nielsen held a large stake throughout. In 2007 Nielsen bought the shares it did not already own for $21 each, in a deal worth about $327 million.

Cover: Audience at a Parisian Theatre I, Giovanni Boldini. Art Institute of Chicago, public domain. Chosen for a theatre audience (counting who is watching).