For anyone advertising into the EEA or UK, Consent Mode v2 stopped being optional plumbing a while ago. It is the mechanism that tells Google and Meta what they are allowed to measure once a visitor makes a cookie choice. Get it wrong and you are not just risking compliance, you are starving your own campaigns of data.

The failure mode is quiet. A cookie banner appears, everyone assumes the job is done, and underneath the platforms are receiving far less signal than the advertiser thinks. Automated bidding runs on that thinner data, and performance drifts down for reasons that never show up on a dashboard.

We check whether the consent plumbing is genuinely connected, not just whether a banner pops up. That means confirming the signals actually flow through in the way the platforms expect. It is unglamorous, and it is one of the most common things we find quietly holding an account back.