You look at a pair of shoes online, close the tab, and the same shoes follow you across the internet. Criteo, a Paris company, built a business on that trick, called retargeting. Its software watched what shoppers browsed on a retailer's site and bid to show them those products elsewhere. Advertisers paid only when someone clicked. In October 2013 Criteo became one of the few French tech startups to list on Nasdaq.

From Film Picks to Ads

Jean-Baptiste Rudelle, Franck Le Ouay and Romain Niccoli founded Criteo in Paris in 2005. The company started as a movie recommendation engine. The founders found a better use for the same math: predicting which product a shopper would buy and when. Criteo charged retailers per click, so a store paid for results instead of views. That model won online retailers in Europe and the United States, and Criteo grew into one of the largest ad tech companies outside Silicon Valley.

Thirty-One Dollars on Nasdaq

Criteo sold 8.1 million American Depositary Shares at $31 each on October 29, 2013, above a range it had already raised. It collected about $251 million. The stock closed its first day at $35.39, about 14 percent higher. Later threats came from browsers and phones that limited the tracking cookies retargeting depended on, and Criteo pushed into ads on retailers' own sites. It moved its legal home from France to Luxembourg in July 2026 and still trades on Nasdaq as CRTO.

Cover: Courtesan Looking Back at Shadows on the Shoji, Isoda Koryusai. Art Institute of Chicago, public domain. Chosen for a figure looking back (ads that follow you after you leave).