Visitors to online casinos and other online gambling sites increased during the month of July, according to comScore. The company, which measures all kinds of Internet statistics, stated that online gambling websites had 13.4 million unique visitors during the month of July. That is an 11 percent increase from June.

So what caused a sharp spike in interest in online gambling during the month of July? No online casino visitors were polled, but it’s a safe bet that it has something to do with a little event during July called the World Series of Poker.

According to Jeff Hackett, Senior Vice President of comScore Media Metrix, the World Series of Poker tournament prompted “millions to visit online gambling sites to test their card-playing skills.” It’s not hard to believe that the tournament, which is now thoroughly covered by the likes of ESPN, among other media sources, would lead to an increased interest in online poker.

Not surprisingly, online poker websites saw the largest gains during July. PokerStars saw an 8 percent increase, Full Tilt Poker saw a 14% increase and Ultimate Bet saw an incredible increase of 33 percent more unique visitors in the month of July.

It is not known how many of those online gambling visitors were from the United States, where the World Series of Poker is held (in Las Vegas). The U.S. federal government currently acts on a de facto online poker ban, thanks to UIGEA, even though no federal ban on online gambling exists.

comScore provides digital marketing intelligence by measuring a variety of statistics for websites, online advertising and online traffic. They use statistical research, analytics and survey tools for their research.