Demo disks are entirely a thing of a past. Gamers older than myself may reminisce about playing short and sweet levels of a game they wanted, letting the hype build up until they were finally able to buy the full game. In case the name didn’t give it away, a demo disk contains a single level of a game to give players a taste of a game before playing it. This was usually a mutual beneficial arrangement. If the game was good, the demo disk could switch a consumer from a “maybe” to a “definitely”. But if it was bad, it would stop the consumer from wasting their money on it.
Although we’ve crossed from the physical to the digital era, there’s no reason for demos to disappear. The first level of a platformer or the first half hour or so of an adventure game could be free to play on steam or hosted elsewhere, and if the players liked it they’d buy the full version. However, even before we went fully digital, game demos had already become few and far between. I’m a young guy, and my first console was the Wii. I have a hard time thinking of demos I had access to, and even if I remembered them all I could probably count them on one hand. For one reason or another, free demos were disappearing.
Now, a cynic would say that corporations stopped releasing demos because that made it easier to release bad or buggy games. They wouldn’t be entirely wrong, but personally I’d say that it was more of a side effect. I think that with the rise of the internet, it was easier to find reviews of games, causing developers to find demos “obsolete”. However, I wouldn’t say that they are. The most important opinion for a gamer is their own, and the best way to get that before shelling out $60 is through a demo. Wasting that much money on a disappointment is a terrible feeling, and most of us on this site would love to see demos come back.