When you write online, there are two metrics that I want to instantly encourage you to ignore.
The first is Followers. When you write on RoyalRoad or any similar website, it's easy to feel elation when you start seeing your followers skyrocket. People gain a thousand followers and think, 'shit, I might have made it.'
It's like winning a comedy competition and thinking that you just became a comedian. It doesn't work like that. You are a comedian when you make people laugh - and a professional one when you start reliably making money from such a practice.
Therefore, you are a professional writer when you start making serious cheddar from your work.
Serious cheddar might be anywhere from $1000 to $5000 dollars based on where you live. In a third or second world country, $1000 a month means you are rich. In a first world country like Italy, which is usually quite cheap outside the bigger cities, $3000 is what might constitute the serious cheddar. In New York? Anywhere below $10000 probably means you might go under if you get any serious extra expense thrown at you, at which point you will be starving or you living in a rat box. With actual rats.
Which metric is probably the best to predict your fiction's success?
In the early days, your retention rate among the first chapters is probably one of the best predictors of how many dead presidents you will be stacking in the future. The retention rate is a good predictor of success on low numbers. However, it starts going down naturally and losing meaningfulness the more you stay in the game.
The second best metric is simply the number of patrons and your monthly gross earnings. That’s what I personally look at. I never cared about views or follows. My novel is doing well if people are paying for it; it’s that simple.
A potentially useful metric might be the churning rate of your patreon.
Taking in only good stuff and pumping yourself up to unspeakable levels might be toxic on the long term and might hamper your growth. But, especially when starting out, very few writers have the fiber to take the amount of shit that internet will throw at them. People on the web are not held accountable for what they say, meaning that they will spout the meanest things about your content. And the thing is that [I believe that written critics are not a reliable metrics of success. And you should Ignore vanity metrics and focus on what really matters. In fact, I firmly believe that Ratings are Vanity Metrics