UK-based online gambling operator Sky Betting & Gaming (Sky Bet) is riding a wave of good news to start the week.

In a regulatory filing, Sky Bet announced that their customer base grew 19% to 2 million in the first half of 2017-2018 financial year, thanks to what the company described as its “busiest” Cheltenham Festival.

Sky Bet CEO Richard Flint said that the company recorded bet volumes of more than 300 bets per second, placed during the festival’s Gold Cup. He attributed the rise of punters to the improvements that they made to their website, which expedited the process of rewarding their customers, and to the algorithm that gave players tailored content. The company also offered customers a money back guarantee during the first race at the Cheltenham festival.

“Our investments in data science are delivering greater personalization to our customers, with the home page tailored towards the individual, and recommended games and bet options delivering relevant and appealing content,” Flint said in a statement.