If you plopped down on your couch with a cold beverage and tub of popcorn for the recent start of the National Football League season, you couldn't have helped noticing something even more striking than Adrian Peterson's return to the gridiron.

Based on what you saw on your flat screen, it would have been easy to conclude that the games on the field have taken a back seat to the fantasy contests being advertised during virtually every break in play.

You're not imagining things. DraftKings, the biggest presence in the fantasy sports market, spent more than $16 million on TV ads during the first week of the NFL season, making it the No. 1 U.S. advertiser during that period, according to media tracking site ispot.tv. DraftKing's chief competitor, FanDuel, was right up there, too, spending about $11 million, good for sixth place.

For those of you new to all of this, fantasy sports involve participants selecting teams of professional athletes who "score" points for players based on what the athletes do in their real games. In the old days, fantasy sports amounted to a few friends slogging through a league season, often without the benefit of a computer, with the hope of winning a few bucks. But organizations such as DraftKings and FanDuel have turned the business on its head by offering hundreds of online contests that allow daily play.

Participants are not stuck in long seasons — the payouts are fast, and they can be big.

The Fantasy Sports Trade Association estimates that more than 56 million people in the U.S. and Canada will take part in fantasy sports in 2015, and they're expected to spend $15 billion doing so — most of it on football.

So what do all these people playing expect to get for all that money they're spending? Fun, recreation, competition — and, of course, the possibility of winning. It's safe to say that players are not forking over that much money because they think they're going to lose.

But despite all of the money being paid out by these organizations, some people do lose. That's the gamble you take when you play.

Oh… there's that "g" word. Federal law says that playing fantasy sports is not gambling (there are, however, five states — but not Minnesota — that prohibit playing). When Congress decided a decade ago to crack down on the burgeoning online gambling market, fantasy sports were given an exemption under what became the Unlawful Internet Gambling Enforcement Act of 2006, based on the contention that the activity is a game of skill.

Still, according to Keith S. Whyte, executive director of the National Council on Problem Gambling, "While fantasy sports may or may not meet legal definitions of gambling, it clearly meets psychological criteria for gambling."

While there is skill involved, Whyte says, at least some of the outcome is determined by chance — and when there is chance, you can lose.

We have nothing against fantasy sports. Our concern is that because fantasy sports are not considered gambling, potential players are not given any of the warnings about the risks of participating — risks that include but are not limited to losing money.

Spending more money than you can afford to lose can obviously cause a significant impact on one's life, especially if the behavior continues despite the consequences. So can devoting so much time to playing that it interferes with the rest of your life, including your personal relationships.

Most who play fantasy sports will have fun and play responsibly. But as the number of people who play these games rises, so will the number who have problems with it.

Trouble could increase simply because there is little or no effort to prevent problems from occurring. Because the websites say what you're doing is not gambling, it makes it hard for them to offer help in preventing problems. If you're a problem gambler, you might justify participating in fantasy sports because they aren't legally defined as gambling.

It just makes good, common sense for participants in these activities — no matter how you may define them — to take simple precautions.

Players should always set limits — don't put more money into a game than you can afford to lose. Don't break that rule thinking you can make up for losses. Don't spend so much time playing that it interferes with your personal life. Don't play to escape personal problems or to avoid dealing with them.

While daily fantasy sports are not legally considered gambling, some of the warning signs of problem gambling can be helpful for players to know. You can visit our website at www.NorthstarProblemGambling.org for information on the warning signs and resources to find help.

And remember that despite all the fantasy sports ads on TV these days — there are still real games on a real field. Take time to enjoy them.

Cathie Perrault is executive director of Northstar Problem Gambling Alliance in Roseville.