In subsequent meetings with officials from the Gambling Commission and its overseers in government at the Department for Digital, Culture, Media & Sport, Prest and his colleagues discovered that the regulator was looking for something similar: It had told operators that it wanted an industry-wide tool to track their customers’ activity, known as a “single customer view.” It seemed a perfect fit.

The idea that he and three fellow bankers hit upon was to build a system providing operators with a birds-eye view of their customers’ betting across the entire market, alerting them to potentially problematic behavior. Firms including Bet365 Group Ltd., Ladbrokes and Paddy Power then enrolled their biggest losers into so-called VIP schemes and showered them with gifts that typically included free bets, cash deposits, tickets to sports games, flights to Las Vegas, and other inducements to keep them hooked, the reformed addicts and current and former employees said. Betting firms have been exploiting that blind spot ever since, developing aggressive habit-forming games tailor-made for obsessive gambling, and cashing in while a significant subsection of their customers racked up huge losses, according to interviews with dozens of current and former employees, reformed addicts, lawmakers, consumer advocates, and academics. The law predated the technological revolution that was the smartphone. Gambling firms were allowed to advertise sports betting, online casinos and poker on TV and radio for the first time, and until 2014 remote operators selling to British customers weren’t even required to hold a UK license. The explosion in online gaming in the UK can be traced to the Gambling Act of 2005.

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