Google chairman Eric Schmidt has said the next step for the search engine would be knowing what users are looking for before they ask.

Schmidt said he could envisage a time when the search engine can predict a user's query or even preempt their search altogether.

He told the Cannes Lions festival: "Google needs to move beyond the current search format of you entering a query and getting 10 results. The ideal would be us knowing what you want before you search for it."

Schmidt said Google could do that if its users were willing to hand over data about their preferences. He added that mobile was the "big development" for tech firm going forward.

Outlining his vision for mobile, he said: "So I'm in Cannes and I want to buy a t-shirt. My phone should be saying you can turn left here and go get 30% off your favourite brand. Then I go to the store and pay for it on my handset. How big a market is that? We're talking trillions of dollars.

"It's very, very targeted advertising. How does Google make money here? We don't make money on the transaction, but we'd make it on the ads because they'd be so valuable.

"We strongly believe that advertising has value. Targeted ads are worth money. But why run a diapers ad on TV if you're not sure the baby is home?"