Add a shared ID solution, or run without one?

Add a shared ID solution, or run without one?

Many browsers block third-party cookies, so advertisers can't tell who they're bidding on. A shared ID solution gives each visitor one privacy-safe identifier that partners recognize.

— With a shared ID: advertisers know more, so they bid higher, but you add another script and a privacy notice.
— Without one: lighter, simpler, fully cookieless, but bids on unknown visitors drop, sometimes 20 to 50 percent.

Tiny example: on Safari and Firefox traffic, where cookies are mostly blocked, a shared ID often recovers much of the lost bid value.

1. Check how much traffic is cookieless.
2. If it's high, test one ID solution.

In plain English: when cookies are blocked, a shared ID helps buyers recognize visitors and bid more.