Rand Fishkin knows how valuable it is for a website to rank high in a Google search. But even he, president of an SEO (search-engine optimisation) firm, was blown away by a proposal he received when he was a panellist at an SEO conference in London, February 2007.

‘Can a poker site rank highly on a Google search using purely white hat tactics – so no spamming, cloaking, link farms or other frowned-upon ‘black hat’ practices?’

Fishkin answered yes, provided the site added other marketing techniques and attracted some media attention.

The rest of the panel scoffed. “Don’t bring a knife to a gunfight,” one chided. After all, this is the cut-throat online gambling sector we’re talking about.

But one poker website owner was intrigued, and he later approached Fishkin. He said, “If you can get us a search ranking in the top five for ‘online poker’ or ‘gambling’ [using white hat methods], we’ll buy that site from you for $10m,” recalls Fishkin, president and CEO of SEOmoz in Seattle. Intrigued but sceptical, Fishkin consulted other gambling site owners at the conference. They said, “If it really does rank there, we might be interested in paying you $10m more.”

A single online gambling customer brings in at least £500 in revenue. With a recent UK Google search of ‘Texas Holdem Poker’ yielding 420,000 results, it’s easy to see why site owners would pay millions to crack the code for Google’s PageRank algorithm.

The stakes are high for online businesses, and Google is the formidable gatekeeper between site owners and their customers. Kinderstart (www.kinderstart.com) is one of a handful of websites that’s sued Google for alleged ’deliberate de-rankings’, although none has been successful to date. A US court dismissed Kinderstart’s claims in March.

Site owners are eager to get their hands on the 75 percent of free Google traffic that’s not affected by AdSense and AdWords, Google’s pay-per-click programs. With 47 percent market share among search engines and three billion search enquiries a month, Google is king.