Google-Yahoo ad deal issue

Google Inc. made an Advertise deal with Yahoo to make it more stronger. Before justify the complete deal, Tim Armstrong, The advertising president of Google inc. announced that as the result of deal that advertisers would not see increased prices but user gets more good performance and good CPC of relevant advertise.

In short, Google's argument here is that the agreement will make Yahoo stronger because it will give more money to reinvest in its own advertising platform. And if it does not make Yahoo stronger? And if Yahoo will take money and throw down the rat hole? There is no guarantee that simply by spending more money on advertising platform Yahoo can deliver more relevant ads. The problem so far has not been a shortage of funds.