Lookalike segments extend to Video brand campaigns

What changed

Google's captured help page limits this option to Demand Gen and Video brand campaigns. Seed data can come from customer lists, website or app activity, or engagement with a YouTube channel. The documented minimum is more than 100 active matched people across the submitted lists. That eligibility floor is different from PPC News Feed's recommendation to use a larger seed.

The narrow, balanced and broad settings trade similarity for potential reach. Google describes target proportions of 2.5%, 5% and 10% of users in the selected location, respectively; these are modelling aims, not promised impression volumes. The help page says segments refresh as customer data changes and advises allowing preparation time before launch. It also describes creating the lookalike in campaign ad-group settings rather than treating Audience Manager as a complete editing interface.

A sensible test starts with the behaviour represented by the seed. A list of frequent purchasers answers a different acquisition question from a list of all visitors. Our interpretation is that choosing a broader setting cannot compensate for an ambiguous seed definition. Keep the campaign objective, seed selection and creative proposition aligned, then compare delivery against a relevant existing audience. Avoid treating a larger estimated audience as evidence of higher customer quality.

Why it matters for advertisers

The expansion offers another way to test prospecting in eligible video campaigns, but similarity is not a business outcome. For example, a repeat-purchase seed could be useful for a replenishable product while being a poor fit for a one-off purchase. Choose success measures that reflect that distinction before increasing reach or budget.