It was announced it June that Google and Yahoo had agreed upon a deal where Google would have the rights to sell search and other text ads on Yahoo sites, sharing the revenue generated with Yahoo. Today the deal has been challenged by some of the world’s biggest marketers.

Google currently have a 76.6% share of the search market whilst Yahoo has 17.9% and MSN have just 5.5%. The deal could generate an extra $800 million for Yahoo who were planning to sell their search marketing division to Microsoft but pulled out.

So who would benefit from this deal and is this just another of Google's bullish tactics to take over the world? They've already acquired DoubleClick last year.