Effective retargeting segments audiences by intent and caps frequency deliberately, rather than chasing every site visitor with the same ad for weeks. Separate high-intent actions, like adding to cart or viewing pricing, from low-intent ones, like a five-second page view, and give each segment its own message, budget, and exclusion window.
Wasteful retargeting usually comes from stale audiences and no frequency cap — showing the same creative to someone who already converted, or to someone who bounced immediately months ago. Exclude converters promptly, refresh creative regularly, and keep retargeting a small, targeted share of total spend rather than the default catch-all.