Email marketing economics for Shopify stores

Your email list is a count of addresses. Your customers are people. Most of the time the two line up, but every person with two subscribed addresses is emailed twice and measured twice. Depending on your plan, the extra profile or send can also raise your bill.

A contact is one address in your email platform. A person can have several: a work and a home email, an old address and a new one, one from a guest checkout and one from an account. In MergeGuard’s demo store: 1,012 subscribed contacts → 926 people; 86 would get the newsletter twice Demo store (Northsail Supply).

Each system decides on its own which records belong to the same person. That process is called identity resolution. Shopify and your email platform can disagree, so one person can be one customer in one system and two contacts in the other.

Email marketing consent is the customer’s choice, recorded per address. Leaving a duplicate address out of your sends keeps their subscription as it is, while unsubscribing changes it.