Not long ago, if a person was inclined to play a fantasy sport, they were somewhat limited to commit to a season-long league. Over an entire season, as players were injured or not performing, the fun factor diminished.

Then came along the rise of daily fantasy sports. If you watch TV, there’s a pretty good chance that by now, you’ve seen advertisements for FanDuel or DraftKings. These daily or weekly leagues allow its users to pick a lineup of players who they think will best perform on that night or week and do it all over again. In other words, it doesn’t make you lock the same players into a season-long situation where your only chance at winning is when the season ends.

What makes these companies so popular and profitable is that they offer thousands of weekly tournaments which give the average football fan a chance to win a large chunk of cash for only a few bucks.

For instance, one has the option to pay $5 to enter a tournament with 50,000 other people. When the week is up, the person with the team who scored the most fantasy points walks away with $200,000 in cash. Payouts are made up to 20,000th place, giving users the ability to win their money back.

There are tournaments that offer $1,000,000 payouts and over the past few years, several guys and gals, just like you and I, have picked the lucky winning lineup and turned into millionaires overnight.

This year, FanDuel, a company with a recent Wall Street valuation of $1.3 billion, will pay out $75 million per week in cash prizes, with over $2 billion expected to be paid out over the course of 2015.

Their closest competition, DraftKings, isn’t far behind.

That should clearly explain why they’re able to buy so much commercial air time. They’re cashing in big time on America’s hunger to bet on sports and daily fantasy sports, and as of now, it’s the only way to legally do that.

I started using FanDuel in 2014 and I’ll be the first to say it makes football — a sport I already love — exponentially more exciting on Sundays if I know I have some skin in the game. Everyone I’ve introduced it to has said the same thing – even those who know little to nothing about the sport.

(To give you an idea of how serious the business is.) Over the summer, FanDuel raised $275 million in funding from both Google and Time Warner, DraftKings signed an exclusive deal with Disney-owned ESPN to be the network’s official daily fantasy sports service.

So, whether you’re a sports genius with a knack for identifying the best players or a non-sports fan who picks their lineups based on how weird a player’s last name is, both have a fairly equal chance at wining. Trust me, I’ve seen both.

Either way, it’s incredibly fun