It largely depends upon the response you get to your answers, which I believe has something to do with algorithms.
In my own experience, I had answered quite a few questions, and had received what I considered normal responses. Nothing up in the hundreds of upvotes and hundreds of comments kind of range. Just ordinary, fun, thought-provoking stuff.
But then, oh my, something I wrote accidentally went viral. I wasn’t trying. I really wasn’t. But in the first twenty minutes I had over 200 upvotes and even more views, and I still have no idea how this sort of thing happens. And, at the time, I thought it was exciting and unbelievable and that it would quickly pass and “normal” would then resume. But I didn’t know then about the algorithms, or about what they would do.
The algorithms (which I envision as tiny robot faeries) noticed that I had gone viral. It got their attention. And they said to themselves “Wow, a whole lot of people are really interested in this!” That happened a few days after going viral, and the views and upvotes were in the thousands and still showing no signs of slowing down. So the algorithms decided to take action. They sent me a message. It said “Your answer to (this question) has been sent to 1,000 people in their daily digest!”
In summary, what happens if you answer a lot of questions and one of them goes viral on Quora is that you’ll discover that more people than you could possibly have imagined actually care about what you have to say, and many of them actually care about you, and if you’re just Joe Ordinary, it knocks your socks off and changes your world, exhausts you but skyrockets your confidence and self esteem, and you discover that you’re actually making the world a better place for hundreds of thousands of people in ways you could never have imagined. So you keep going. In my mind, I imagine the voice of Ringo Starr whispering at me “do it for the fans, mate.”