That's amazing if true, though it sounds unbelievable to me. Given the other statistic that "[o]ne in two American adults buys a lottery ticket at least once a year, one in four buys one at least once a month" the avid players at the edge must be spending a heck of a lot for that to add up...
I don't gamble at all, but I tend to think of lottery tickets as pretty harmless. I've never seen anybody show up to a gas station and buy more than a few dollars worth of tickets, though I'm sure there are outliers who would. It's just hard for me to credit this given my back of the envelope math and personal experience. Hopefully the actual book has citations and I can check on it.