Travelocity bought rival Preview Travel. Priceline.com, meanwhile, gained recognition as it expanded from airline tickets, hotel reservations and car rentals into car sales and even groceries. Web publishers continued to gain prominence. The Internet Advertising Bureau reported the top 10 publishers garnered some 75% of all Internet advertising revenue in the second quarter of '99. It also said Web advertising is on track to hit $4 billion by yearend.