Hard question. To be honest, I think that most ideas that work well with a story game format won't be that effective when you translate it into a linear novel. It's a completely different medium. Eternal wouldn't be Eternal if it was a book. Hell, it would be a nightmare to even choose what to take from what path if one wants to make a linear adaptation out of it.
Well, with works like the featured story game of the romance corner Demonologists, I could see such transition work better. Mainly because the story is so linear and devoid of "gameplay" that it would honestly work better as a novella. You could then argue that the concept wasn't working that well as a story game and yeah, you may be right on that part.
For me, deciding what kind of branching structure I want comes first, the idea comes second. Like, "one story please" is playing around with the idea of having flashbacks influence the ending while in story only a few hours at most had passed. With 'It's a boy", well... I knew it was downright unpublishable. (I've once really considered making a censored version or change some details into more palatable ones such as having the offspring making scenes be more like the alien movie, but eventually decided against it.) I'm actually still a bit shocked that it was not immediately removed and that many people sorta liked it.
As for monetizing
I Honestly don't think I'm good enough to write something people would want to buy. Like drawing, writing is just a hobby of mine. Ever since I've got access to the internet, I've been reading lots of webnovels and webcomics and I still do admire these authors (eleven year old me didn't have money to buy many books and the local library was very small) So I think it's also a nice idea to have things I write online for free. Then again, most of it is just self indulgence. I rather want someone else to take my ideas and write the cool story I had in mind so that I don't have to the shitty work while enjoying the end product. Since that's impossible, outlining it for myself would do.
the story idea
Story idea from my pile of outlines that would work the best in linear fashion: I always thought these fantasy adventurer guild systems were very sketchy if they were to exist in real life. So here it is:
Stereotypical dungeon in stereotypical fantasy world emerges, a traditional 19th century style company town forms around it. In exchange for housing and repayment of previous made debts, the company heirs employees, ahum, "adventurers" to delve deep into the dungeon and extract treasure from it. Deaths, injuries, attempted strikes, withholding pay and piling debts ensue, in short, it's a shitty job.The protagonist, a guy who had to pay off his dead gambler dad's debts, becomes an adventurer and forms a party with even more desperate people. Slowly they clear more and more floors, hoping that at the deepest part of the dungeon they will encounter a treasure that will let them finally quit.
If this idea had been executed before, please let me know. I actually want to read a story based on such a concept, but I couldn't find any so far that hit this particular angle.