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Getting Ad Audiences

How to turn MoltSets contacts into privacy-safe advertising audiences — hashed email match keys for customer match, and MAIDs for mobile retargeting.

Three endpoints convert a known contact into identifiers you can upload to ad platforms. All of them return hashes or device IDs rather than raw personal emails, which is what makes them usable in customer match and custom audience workflows.


​Choose the right endpoint

You have

You want

Call

LinkedIn URL

The widest possible set of match keys

linkedin_to_sha256

Business email

Hashed personal emails to match on

business_email_to_sha256

Any email

Mobile device IDs for in-app targeting

email_to_maid


​Maximise match rate with linkedin_to_sha256

Match rate is the whole game with customer match uploads — a platform can only find the users whose identifiers you supply. linkedin_to_sha256 returns the broadest set MoltSets holds for one person: both address types, in both hash formats.

{
"linkedin_slug": "john-smith-123",
"business_SHA256_array": ["..."],
"business_md5_array": ["..."],
"personal_SHA256_array": ["..."],
"personal_md5_array": ["..."]
}

Four arrays, not four values — a contact with several known addresses returns several hashes per array. Upload everything a platform accepts. Supplying both SHA256 and MD5 where supported, and both business and personal addresses, is the single biggest lever on match rate.


​Bridge work identities to personal devices

business_email_to_sha256 takes a business email and returns hashed personal emails:

{ "personal_email_SHA256": ["..."] }

This is the endpoint that solves a specific B2B problem. Your CRM is full of work addresses, but people are logged into Meta, Google, and TikTok with their personal accounts — so uploading work emails to those platforms matches almost nothing. This crosses that gap without ever exposing a raw personal address.


​Reach devices with email_to_maid

email_to_maid resolves an email to one or more Mobile Advertising IDs — AAIDs on Android, IDFAs on Apple. These are the identifiers ad platforms use to target a specific device.Use it for mobile retargeting, programmatic activation, and cross-device campaigns where you want to reach a known contact in-app rather than in an inbox.


​Where these go

The hashes returned by business_email_to_sha256 and linkedin_to_sha256 upload directly to any platform supporting customer match or custom audiences — Meta, Google, LinkedIn, TikTok, and others.

Check each platform’s expected hash format before uploading. Most customer match products expect SHA256 of a normalised, lowercased email; a few still accept MD5. Supplying the format a platform doesn’t expect is the most common reason a well-built audience matches at near zero.


​Build the audience, then activate it

The full path from an ICP to a live audience is a search followed by a hash lookup:

  1. with your ICP filters → contacts with LinkedIn URLs search_people

  2. linkedin_to_sha256 on each URL → hashed match keys

  3. Upload to your ad platform as a customer match audience

Starting from a contact list you already own instead, business_email_to_sha256 takes work emails straight to personal-address hashes in one step — no LinkedIn URL needed.


​Practical notes

  • Only pay for hits. Tokens are charged only when data is found and returned. Contacts with no resolvable identifiers cost nothing, though the request still counts toward your rate limit.

  • Audiences decay. People change devices and reset advertising IDs; MAIDs go stale faster than email hashes. Rebuild rather than reuse an old upload.

  • Mind platform minimums. Most ad platforms won’t activate an audience below a minimum size, and a list that matches thinly can fall under it. Check results.total on your source search before committing to the enrichment run.

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