Upload a customer list to Google Ads and keep it working

1. 1Export every customer you have, with every contact detail you hold: email, phone, first name, last name, country and zip. Google matches on each key separately, so a customer with an email and a phone has two chances to match.
2. 2Name the columns exactly Email, Phone, First Name, Last Name, Country and Zip, in English. A customer with two emails or phones can have a second Email or Phone column. A name only matches with all four of First Name, Last Name, Country and Zip present.
3. 3Write phones with the country code, as +12345678910. Write the country as a two-letter code such as US on every row, even if every customer is in one country. Zip can be five digits or ZIP+4.
4. 4Strip titles such as Mr. and suffixes such as Jr. from names. Google says email addresses with accented letters do not match, so fix those or leave them out.
5. 5Give every row the same number of commas as the header row, leaving a blank between commas where a value is missing. Save as CSV in UTF-8; Google does not accept UTF-16.
6. 6Leave the data unhashed. When you upload plain text, Google hashes the email, phone and names with SHA256 on your own computer before anything is sent. A judgment: since Google already hashes it on your computer, hashing it yourself mainly adds a way to get it wrong.
7. 7Click Tools, open the Shared library drop-down and click Audience manager. Open the Your data segments tab.
8. 8Click the plus button and choose Customer list. Name it by who is in it, such as All past customers, not by a date, because the same list will be refreshed.
9. 9Upload the CSV and tick the box that says the data was collected and is shared in compliance with Google's Customer Match policies.
10. 10Set the membership duration to 540 days, the maximum. Google's help page for editing a list describes the default as unlimited, but its policy stops counting any member not added or updated in the last 540 days, so 540 is what you get either way.
11. 11Click Upload and create (some Google pages call it Upload and create list). Processing can take up to 48 hours. The success page shows how many rows uploaded and the match rate.

The match rate says whether the file was readable, not whether the list will work. Google calls it an indicator of formatting, not performance.

1. 1On Smart Bidding, any tier: add the list to each Search campaign as Observation: Campaigns, Audiences, keywords, and content, Audiences, Edit audience segments. Google says first-party segments added as Observation are used as signals for Smart Bidding, and the Audiences report then shows how those people behave. Do not count on Search picking the list up unadded: Google says automatic inclusion covers YouTube and will soon reach Search ads, although a table on another of its pages lists Search as launched in 2023.
2. 2To stop paying for clicks from existing customers: add the list under the campaign's audience exclusions. Every tier can exclude. A judgment: exclude it from campaigns meant to win new customers, never from a campaign on your business's own name, because past customers search the name to find your number.
3. 3To have Google bid only for new customers: open Goals, Conversions, find Customer lifecycle optimization and click Edit goal. Tick the list under Existing customers definition and click Apply. Then in the campaign's settings, under Customer acquisition, choose Only bid for new customers. Google recommends that mode for lead goals, and it needs a Smart Bidding strategy: Maximize conversions, Target CPA, Maximize conversion value or Target ROAS. For non-retail advertisers, Google also requires purchase conversions from the last 30 days or an existing-customer list before the goal can be enabled, so a business that tracks leads rather than purchases needs the list.
4. 4On an account above the spend tier: you can also use Targeting to show a campaign only to people on the list, for example a seasonal service offered to past customers. Google forbids combining a list with other targeting, such as a small area, so tightly that the ad reaches only a handful of people.

Google's pages disagree on the size new-customer bidding needs: one says 100 active members, the Performance Max store goals setup page says 1,000, and a third warns that a list under 1,000 may limit the goal's ability to work. Plan on 1,000 before relying on it.

1. 1Set a reminder to refresh the list every three months, a judgment that leaves plenty of room inside the 540 days. In Audience manager, click the list, click the three-dot icon in the Customer list panel and click Edit.
2. 2Choose Add more customers and upload a fresh export of your whole current customer file, so new customers join and existing ones are updated. Set 540 days again and click Save.
3. 3Use Replace existing list members with a new customer list only to drop people on purpose. Google says appending rather than replacing helps maintain the list's size.
4. 4When a customer asks to be taken off, upload them through Remove specific customers on the same edit menu.
5. 5If the list was first uploaded before 1 February 2024, refresh it now. Google holds older lists to the old bar of 1,000 matched users until they are uploaded or refreshed again; refreshed lists need 100.

Do not refresh more often than the list finishes processing. Google says a list updated faster than it processes shows In progress permanently, even though earlier updates finished.