10/30/2026
Someone just sent you a Google Ad Manager invite to approve an "MCM Manage Inventory request."
You're now reading Google support docs at 11pm, wondering if you just handed over your ad stack.
Quick reality check: MCM is a permissioning layer. It's how an approved partner connects your inventory to Google Ad Exchange demand. No MCM relationship, no AdX bids in your auction.
The part most publishers skip is the delegation type, because it decides who controls serving and who gets paid.
Manage Inventory: your inventory runs through the partner's network. Simpler setup. Google pays the partner, the partner pays you.
Manage Account: the GAM account stays in your name. The partner operates inside it, and Google pays you directly. More overhead, more visibility.
Neither is better by default. Before you approve, pin down four things:
1. Who has trafficking rights
2. Who sets price floors
3. Whether your direct-sold campaigns keep running untouched
4. How reporting reconciles between your partner and Google
We broke down the full picture, including how MCM differs from GCPP and direct AdX access.
Link in comments.