^^
This.
Usually cheap games and demos of games.
I remember a long time ago right after I got my first computer, I bought this "1001 games" CD and it was full of demos, several hundred card games, etc.
There were like... 2-3 decent games on it, but they were demos. And one of them I already had -- Castle of the Winds.
No viruses or adware or anything, but this was a *long* time ago, like 10+ years ago. Lots of DOS games and Win3.1 card games, etc.