Ad arbitrage without proxies is like gambling with an empty wallet. Ad platforms (Facebook, Google Ads) strictly watch IPs: login from a new address, then another — and the account is flagged. Proxies solve this: each account gets a stable IP of one region.
The main rule of an arbitrageur: do not change IP without need. Ad systems love stability. Rotation is harmful here.
Proxies for Facebook and other systems must be clean: not burned in spam. Take a pool that the seller keeps clean, not shared lists.