Why bought followers drop
Instagram removes fake accounts in regular sweeps. If your followers are bots, you lose hundreds or thousands overnight, and the reach penalty stays even after they're gone.
Followers that don't drop in waves
Real people are followers that don't drop off in purges. Like any audience, a few may unfollow over time: someone moves on, closes their account, changes interests. That's normal, and it's nothing like a bot purge.
Nobody can honestly promise permanent
Anyone selling permanent followers who never unfollow is promising something no real audience does. What we can say: real people who chose to follow you, and who stay the way real followers stay.
How to keep them
- Keep posting: people stay for content.
- Reply to comments and messages.
- Keep your account public.
- Post for the place your followers come from.