Audience signals for Performance Max

Performance Max doesn't use keywords or fixed targeting. Google's AI decides who sees your ads across Search, YouTube, Display, Discover, Gmail and Maps (see Google Ads: Search vs Performance Max). An audience signal is how you tell it where to start looking.

What an audience signal is, and isn't

An audience signal is a description of the people most likely to become your customers. You add one to each asset group.

• It is a starting point. It helps Google's AI learn faster, especially in a new campaign with little data.
• It isn't targeting. Google can, and will, show your ads to people outside your signal if it thinks they're likely to convert.

So if you need hard limits, such as only showing ads in one area, use the campaign's location settings, not the audience signal.

What they're used for

• Shortening the learning phase, so less budget goes on finding the right people.
• Steering a new campaign towards your best customers, rather than whoever is cheapest to reach.
• Giving each asset group a clear audience to match its message.

What goes into one

A signal can combine four kinds of information, roughly from strongest to weakest:

1. Your data. People who already know you: website visitors, customer lists (email addresses you have permission to use), app users and YouTube viewers. This is the strongest signal you can give, because these are real customers.
2. Custom segments. People described by what they search for, the kinds of websites they visit or the apps they use. For example, people who've searched for "emergency plumber" or "boiler repair", or who visit competitors' websites.
3. Interests and detailed demographics. Google's ready-made groups: interests (affinity), people actively researching a purchase (in-market), life events such as moving home, and detailed demographics such as homeowners or parents.
4. Demographics. Age, gender, parental status and household income. Use these to sharpen the picture, not on their own.

How to build a good one

1. Start with your own data. Add your website visitors (this needs your Google tag in place, see Tracking tags in practice) and, if you have one, your customer list. Even a small list helps.
2. Add a custom segment built from searches. List 10 to 20 searches your best customers would actually type. Be specific: "accountant for small business Croydon" beats "accounting". Google recommends search-based custom segments.
3. Add competitor and related websites. In the same or a second custom segment, add the web addresses of competitors or sites your customers use.
4. Add a few relevant in-market or interest segments. Only ones that clearly fit. More isn't better.
5. Use demographics sparingly. Only if they genuinely define your customer.
6. Match the signal to the asset group. If one asset group sells to homeowners and another to landlords, give each its own signal, images and headlines.

A worked example

A bookkeeping firm in Croydon wants new small business clients. Its signal might be:

• Your data: website visitors from the last 90 days, plus a list of existing clients' email addresses.
• Custom segment (searches): "bookkeeper for small business", "vat return help", "self assessment accountant", "making tax digital software", "bookkeeping services croydon".
• Custom segment (websites): two local competitors' websites and a popular accounting software site.
• In-market: relevant business services segments, such as accounting.
• Demographics: left open, because small business owners come in all ages.

Search themes: a related tool

Alongside the signal, each asset group can have up to 50 search themes: topics or phrases your customers search for. They work like broad or phrase match keywords, helping Performance Max show on Google Search for things your website doesn't make obvious, such as a new service or a promotion. Don't repeat near-synonyms: "car" and "automobile" reach the same people.

Google has folded some custom segment features into search themes, so it's worth adding your most important searches as search themes too.

Ruling things out

Because a signal isn't a limit, use these when you need to exclude something:

• Locations and languages in the campaign settings.
• Negative keywords at campaign level, available to all Performance Max campaigns since 2025.
• Brand exclusions, so you don't pay for people searching for other brands, or for your own if you'd rather cover that with a Search campaign.

After launch

• Give it time. Expect a learning phase of a week or two before judging results. See The learning phase explained.
• Check the Insights page. It shows which audiences are actually converting, which often differs from what you expected. Use that to refine the signal.
• Keep your lists up to date, especially customer lists.

In Snifferdog

Snifferdog sets up your targeting from the target audience, locations and age range in your brief, so the more specific your brief, the better the starting point. See How to write a great brief.

Using your own customer lists and website visitor lists in Snifferdog is coming soon. Until then, you can add them to a Performance Max audience signal directly in Google Ads.

Read more: Google's guides, About audience signals for Performance Max campaigns and About search themes in Performance Max campaigns.