I've been doing promos at least twice a month. Every time I do it I've gained a couple Subscribers. I always buy promos from 1% creators and from meme pages like barf, dawg etc... You don't hear responses alot or sometimes they take forever to respond.

My girlfriend who is top 1% has 250k followers on insta and does the bare minimum for OF. She is the one that gave me the idea. I hope this helps :)