Fastclick lasted less than six months as a public company. The Santa Barbara ad network matched advertisers with thousands of smaller websites that were too small to sell their own ad space. Site owners pasted in Fastclick's code and got a share of every dollar. When Fastclick went public in April 2005, online advertising had recovered from the dot-com crash, and Google's AdSense had shown how much money sat in the long tail of the web.

The Long Tail of Websites

Fastclick built its business on sites that big ad sales teams ignored. Advertisers bought campaigns, often paying by the click or by the action a user took. Fastclick's software decided which ad to show on which site to get the best result. Publishers earned a cut without hiring anyone to sell ads. The model depended on volume: many small sites, many ads and a small margin on each.

Bought Within Months

Fastclick priced its IPO at $12 a share in April 2005 on Nasdaq. Four months later ValueClick, a larger online ad company from Southern California, agreed to buy it in an all-stock deal. Press reports valued the deal at about $214 million, based on ValueClick's share price when it was announced. The acquisition closed in September 2005, and Fastclick became part of ValueClick's ad network.

Cover: Two Horses Walked by a Jockey, Jean Louis André Théodore Géricault. Art Institute of Chicago, public domain. Chosen for racehorses (fast).