My growth has been pretty non-existent except for one short spike in new subscribers last month, when my comic was featured in the list of Rising Stars on Webtoons.
Went from 31 subs to 1,120 in about two weeks, gaining subscribers steadily every day until my comic was removed from the list. Since then, the number's fluctuated a little by a couple subs, and is now at 1,115 subs with 5,441 views.
I wish I knew why my comic was placed on the list, and who discovered it in the first place (how does the process of being chosen for that work?)... But I'm very glad it happened anyhow, because I don't market myself AT ALL and I'd probably still be at 31 if not for that ^^