Search and gambling specialists are telling business reporters that Google will see £300 million, or $600 million, a figure significantly higher than the previously reported £100 million figure.

More brands are likely to opt to exploit Google’s market opening. This move may have a major affect on Yahoo and Microsoft, with the former having cited gambling as a key search channel.

Rob Allan, Ladbrokes online marketing manager, said his firm is considering moving a major part of its multi-million-pound search spend to Google.

“We’re increasing spend but also looking at where that money would be best spent,” Allan said. “Google has significant market share and is where many people go to first online, so Yahoo and Microsoft are not as good from that perspective. I can guarantee that over the next month or so money will come out of Yahoo and MSN,” he added. “The question now is, given Google has 80% market share, do we place the same share of spend on it?”

Paul Lewis, Betfair’s head of marketing acquisition, hinted at an increased focus towards Google. “Yahoo and MSN has typically been a smaller channel for acquisitions in the PPC search market but one that we’ve had to focus on while Google was not available,” he said.

Another source, Simon Prodger, marketing director of poker site PKR, said, “It has been very frustrating not being able to work with Google, considering how valuable search is,” he said. “It’s the biggest search engine so it wouldn’t surprise me if gambling companies focus their attentions on Google, especially in the short-term.”