Putting it online for free

So I think a lot of us are familiar with The Martian being online for free first, then put onto the Amazon store later after developing a fanbase. The Worm parahuman series is online too, and seems to have a large fanbase.

Is this a viable model for an unknown to get noticed? Video games have a lot of free base game stuff to get noticed, then monetize later or in the deeper parts of the game.

What do you think about it? What do publishers think about it?