Performance Max is now the default campaign type Google recommends for most advertisers. In Japan, the results vary more than Google's marketing materials suggest. This guide is based on managing PMax campaigns for Japanese businesses across retail, professional services, and B2B lead generation since the format launched in 2021.

Audience signals are not optional

PMax without audience signals is PMax on autopilot. The algorithm will find conversions eventually, but it will spend a lot of budget on low-quality traffic first. Before launch, build audience signals from three sources: GA4 audiences of high-intent visitors, customer match lists from your CRM or email list, and custom segments based on search terms your ideal customer would use. Feed all three into the campaign before it goes live.

Asset group structure for Japanese campaigns

Japanese search behavior is more category-specific than in many Western markets. Users searching '渋谷 歯科' and users searching '渋谷 矯正歯科' have different intent. Build separate asset groups for each distinct service or product category, with headlines and descriptions written specifically for that intent. Generic asset groups with broad headlines perform poorly in Japan because the ad relevance score suffers.

Monitoring the search terms report

PMax's search terms report is limited compared to Search campaigns. You can see queries that drove conversions, but not all queries that drove clicks. Export the report weekly and add irrelevant terms to your account-level negative keyword list. Note that negative keywords in PMax must be added at the account level or via a campaign-level negative keyword list, not at the ad group level.

When to use PMax and when not to

PMax works best when you have clean conversion data, a product or service with broad appeal, and a budget of at least ¥300,000 per month. For niche B2B services with a small target audience, or for businesses with fewer than 30 conversions per month, a standard Search campaign with phrase match keywords will typically outperform PMax. The algorithm needs volume to learn.

The first 60 days

PMax campaigns have a longer learning phase than Search campaigns. Expect the first 30 days to be inefficient. Do not make major changes to asset groups, budgets, or audience signals during this period. After 60 days, you will have enough data to evaluate which asset groups are driving conversions and which are spending without results. Pause the underperformers and reallocate budget.

Performance Max is a useful tool when it is set up with the right signals and monitored consistently. If your PMax campaign is spending but not converting, the free audit will show you exactly where the budget is going.