Regulators and creators of online sports sites such as DraftKings and FanDuel might be arguing whether weekly fantasy sports betting constitutes "gaming" or "gambling," but the distinction means little to Susan Campion, a University of Minnesota addictions counselor.

She anticipates the same rise in gambling addictions that came a few years ago with the emergence of online poker — only with the potential to be worse because fantasy sports sites will lure the casual players who don't distinguish betting on one of the sites from their office NCAA pools and friends' fantasy football leagues.

"It looks like you can start with $20 and you can tell your partner that you put in $20 or $200 to get the match for $200 or whatever," she said. "What they don't know is you are secretly putting more and more money in because it's all on credit cards."

Televised football games have been blitzed with ads for the sites, which offer the popular option of selecting a new fantasy lineup of football players each week and competing for big money against others selecting their lineups.

That element of expertise in selecting lineups — compared with the randomness of a blackjack deal or a roulette spin — is what FanDuel and DraftKings have used to argue that they offer gaming rather than gambling. Campion said that certainly taps into the same ethos of the NCAA basketball office pool — the chance for someone to win money against peers by proving he or she is "smarter than the other guy."

A key difference is that the sites offer daily opportunities to bet and to lose and to fall into the trap of needing a big win to break even, she said. For addicts, the daily "action … triggers the brain in the same way as cocaine — feeding it, feeding it, feeding it."

Campion's therapy groups include gamblers who quietly lost their family savings, betting with as many as 50 credit cards they obtained through private post office boxes. None yet whose addictions were centered on the relatively new fantasy sites, though.

One group member recently said he has an 11-year-old son playing on one of the sites with the help of a friend's parent. The son doesn't know of his father's addiction.

"It's going to be people that don't see this as possibly causing harm," Campion said, "that see it as something they can control because it's not the casinos, it's not whatever — that it's skill. People justify that it's skill."