Yahoo! has completed its acquisition of online ad exchange Right Media; giving it a boost in its battle with Google and others in the internet ad space.

The deal, first announced in April, sees the web giant picking up an ad sales platform that it claims is used by more than 20,000 buyers and sellers a day.

It is also seen as Yahoo!’s answer to Google and Microsoft’s buyouts of Doubleclick and aQuantive – both of which are yet to go through.

Yahoo! paid out a reported $40m when it bought a strategic 20% stake in Right Media in October. In a statement, it said the remaining 80% had ended up costing $650m.

That figure, however, is lower than first announced because of Yahoo!’s sliding stock price. 

See our recent interview with Right Media founder Michael Walrath on what the acquisition will mean for the company, and what the exchange offers to advertisers and publishers.