Gonna be honest: absolutely no clue.
I know that I was on the community tab feature 3 times during lthe first year I was publishing my comic (this is back in 2021 or 2022 when that was still a thing, I've noticed they've changed the app layout now so it doesn't look like that exists anymore), and that would give me a bunch of subscribers and the amount that would sub grew exponentially as the comic got longer so the first time i was on there I got like 16 subs in 3 days which was something like third of my subcount at the time so it felt massive, the last time it was closer to 50 in the week.
As to how I got on the list? No idea. I didn't post on the forums at the time, my actual first forum post is asking what the f happened after the 2nd time and people here explained it. I know that sci-fi's a small community so there's less direct competition than genres like romance that are oversaturated, so I'm pretty sure that helped too, there was also a "top in genre" on the app at the time and I eventually got on there a lot.
But yeah no promotion threads, no sub4sub, and most of the people who I'd hyped prior to publishing are french and were waiting for the french version to come out around 4 months later iirc so I just got really lucky that someone on the tapas team must've noticed the first few pages and liked it well enough. Not a good business model, don't copy, it's not reliably replicable.
