13 April 2007: Google sets the cat among the pigeons in the online display market when it buys DoubleClick - the world's pre-eminent digital ad serving company - for $3.1 billion. Google's chief, Eric Schmidt, assures rivals there will not be anti-trust implications.
30 April 2007: Yahoo! responds almost immediately by paying $680 million to complete the purchase of the internet advertising exchange company Right Media. Yahoo! had already acquired 20 per cent of the company in 2006. Terry Semel, the chairman and chief executive of Yahoo! hails the deal as further evidence of his company's determination to build the industry's leading "advertiser and publisher ecosystem".
16 May 2007: Now AOL clambers aboard the bandwagon, snapping up the mobile ad serving company Third Screen Media, then a day later announcing it has succeeded in a bid for Adtech, a leading international online ad serving company based in Frankfurt. Randy Falco, the chairman and chief executive of AOL, boasts of the company's "incredible momentum" in the ad serving business.
18 May 2007: And Sir Martin's Sorrell's WPP crashes the party too, paying $649 million to buy the internet advertising broker 24/7 Real Media. As the deal closes, it is revealed WPP had been negotiating to acquire DoubleClick before its sale in April to Google.
7 November 2007: AOL maintains its own momentum when it pays $350 million to snap up Quigo, a specialist in selling targeted contextual ads and sponsored links, matching advertisers to specific online article subjects. Quigo already had a relationship with AOL's parent Time Warner - many of the group's sites already used its services.
Fast forward ...
January 2008: But advertisers decide enough is enough when Google announces that it is now in negotiations to acquire Yahoo! in what will be the deal of the decade. Ad industry groups on both sides of the Atlantic call for ad serving to be handled by totally independent organisations and for market remedies to counter Yahoogle's growing stranglehold of the online display advertising market.