It has been argued in the past that casino games, in and of themselves, aren’t all that interesting. According to this line of thought, players are only interested in these games – which, to be fair, are usually pretty simple – because of the gambling aspect and the chance to potentially win money by playing. Without that opportunity, nobody would be playing blackjack, slots, or poker.

But for a lot of people, this is obviously untrue. Social casinos do not give players the chance to win cash, and in most cases, they can’t even win any sort of prize by playing. Instead, they allow users to play slots and other games for free, just for the fun of it. These free to play sites and apps aren’t just enjoyed by a few people here and there, either: they have become some of the most popular programs for desktop, smartphones, tablets, and Facebook users throughout the world, all proving that these games can be entertaining and engaging even when there isn’t necessarily anything on the line on each spin.

To understand the appeal of these casinos, it’s probably first important to understand the concept of social gaming. This term usually applies to the kinds of light, easy-to-play titles that are seen on social media sites and in downloadable apps, either available for free or for a very small cost. If you’ve played Angry Birds, FarmVille, or Candy Crush, you’re familiar with the type of lightweight, casual experiences we’re talking about under this label.

But these famous games aren’t the only popular titles in this genre. Casino-style apps have proven to be just as popular as the biggest puzzle, war, or building games, sometimes attracting millions of users. And when you think about the standard criticisms of gambling games and the needs of users in this market, it starts to make sense. All of the titles we’ve mentioned are easy to play, offer quick, short-term goals, and dole out rewards at a regular pace to keep players interested – exactly what you get from a slot machine or blackjack table.

That makes these and other casino favorites perfect fits for the casual market. Anyone can spin the reels and feel a quick jolt of excitement when they match five symbols in a row. Dice and card games offer at least a little bit of interactivity and have the same potential to light up a player’s eyes when they make an unlikely hand or win a big virtual bet. And don’t forget the key word in all of this: casinos are truly a social experience, so being able to share your victories with friends or compete with them in a free money poker game is a big part of what makes these not-quite-gambling apps so successful. Throw in the fact that this all exists without any betting or financial risk to players, and you have a winning combination for casual play.

That’s not to say that there isn’t money in these apps. In fact, there’s a whole lot of cash to be made by developers, even if there’s no real betting going on in their games.

Earlier, we pointed out that these apps are almost always free-to-play, meaning that players are not charged anything for downloading or playing the games (and in the case of casino apps, there is no way to wager for real). However, that doesn’t mean that there aren’t ways in which developers can’t monetize their products, and they’ve managed to do so in a big way.

One of the simplest ways to make money off of these games is the inclusion of ads – and you’ll often see plenty of advertisements while you play any of them. But even bigger has been the addition of microtransactions: small purchases players can make for various in-game perks that are not essential for basic play, but which many players might be willing to buy at the right price.

For instance, consider a game like the infamous Game of War: Fire Age. Sure, you can sign up and build your army for free. But would you like more gold? You can purchase some, for a price. Want to speed up the cooldown timers that dictate how quickly you can do just about anything in game? You can have that too, if you’re willing to pay for it. In other games, you might be able to open up additional levels or get additional special items if you’re willing to spend a few dollars. Sometimes, players can spend shocking amounts of money on these games.

How does this translate to social casinos? In pretty much the simplest way possible: you can buy virtual chips using your real money. In most of these apps, you’ll be given a certain number of chips that you can begin playing with, and that’s enough for you to enjoy whatever you might want to play. However, should you run out of virtual currency, you’ll be stuck and have to wait until it refreshes (players in these apps are usually given a minimum number of chips each day if they run out). That is, unless you’re willing to pay a small cost in order to buy more chips – often far more than you would normally start with – immediately. Other purchases might include perks that allow you a better chance to win (after all, these aren’t real money games, so they don’t necessarily have to be perfectly random or fair all of the time), clothes or accessories for your in-game avatar, or other little benefits that could help you stand out from the crowd.

At social slot sites, players have two types of in-game purchases available. The first of these is to simply buy coins - the equivalent of in game credits that can be used to play free slots. The second is tied into the purchase of coins - users are asked to buy bundles in order to unlock slots. These games can be locked by putting in a lot of man hours - hundreds at least. The quick way to access the full suite of games is to simply buy enough coins ti unlock them.

You might be wondering whether any of this actually works. How much money, you ask, could players actually be spending on these “free” games? The answer, it turns out, is “a whole lot.” Social casinos were expected to generate a staggering $3.4 billion in revenue for their creators in 2015, even as the total number of players at these sites has begun to drop. This is due to the fact that the vast majority of casual gaming players will spend little or no money over their lifetimes, while a very small percentage of players will drive the majority of revenues. And those who spend seem to do so at an even greater clip when it comes to casino games: one study from 2012 found that paying users averaged nearly $70 in casino apps, compared to a little over $35 per paying player in other social games.

Despite all of the great games available and the presence of monetization features, few would mistake a social casino for an actual gambling experience. While these games can be a lot of fun to play, there is some truth to what we said at the top of this page – the games you can play aren’t quite the same without the potential to win real money.

But that’s only a problem if you see these games as a substitute for “real” casinos, which is not what they’re meant for. Instead, these apps should be treated as their own unique product: something that takes the general look, feel, and action of a casino and turns it into a light, fun experience with no money at risk. For many players, this makes for a much more relaxed experience, as there are no concerns in the back of their mind over the possibility of losing money by playing.

One final word of warning: it’s uncertain whether social casinos are safe for those who have compulsive gambling problems. Research on the topic appears to be mixed: some players may be triggered to bet real money by playing such games, while others may be able to get over their urges without spending any money, which could provide at least some temporary benefits. If you have any concerns over your gambling habits, it may be best to tread carefully in free-to-play gaming apps as well.