Microsoft is "clearly going after the advertising world" and has pledged to invest $2bn to do so, he said. But he said the company is at a "critical point".

"The number-one threat to Microsoft is decreased relevance of its core products", from things such as Web 2.0 technologies and the Ajax web development technique, Smith said.

"Google's concept is empowering the consumer... and the consumerisation of IT" in which individuals bring the technology they use at home to the workplace and thus accelerate corporate adoption of consumer technologies such as with Gmail, he said.

As far as the power struggle goes between Google and Microsoft, there will be no clear winner or loser, Weiner and Smith predicted.