There are 2,000 email addresses in your Square account

A used auto parts shop in Greenwood let me look at their Square account last month. Four years of transactions. 3,400 customer email addresses collected at checkout, one digital receipt at a time.

They had never sent a campaign. Not one.

The owner thought email marketing was something you built from scratch, by convincing strangers to fill out a form on a website nobody visits. He did not know Square had been building his list for him the whole time.

Does your POS collect email addresses?

Yes. Every time a customer pays and chooses "send my receipt by email," Square adds their address to your Customer Directory. Toast, Clover, and Lightspeed do the same thing. The record includes their name, email, visit count, and average spend.

Go check your Customer Directory right now. You might have 200 addresses. You might have 4,000.

A shop doing 10 transactions a day adds somewhere between 600 and 1,500 email addresses per year, assuming 30 to 40 percent of customers choose digital receipts. After three years, that is 1,800 to 4,500 contacts. Most shops have never touched them.

How much is that worth?

Email returns $36 for every dollar spent, according to the 2024 Litmus State of Email Marketing report. That is the average across industries. A list of people who already bought from you should outperform it.

Run the math yourself. Take your total customer email count. Assume 60 percent are still deliverable after churn and dead inboxes. Multiply by a 25 percent open rate. Then by a 2 percent click-through rate. Then by your average transaction.

For the Greenwood auto parts shop: 3,400 addresses × 60% deliverable = 2,040. × 25% open = 510. × 2% click = 10 people. × $95 average transaction = $950 per email.

He was running $400 a month in Facebook ads. Trackable return: $180.

You've been buying ads to find new customers while ignoring the ones who already paid you.

Smaller shop: a gym in Carmel with 800 email addresses collected over three years. Same rates. That is four to five customers per send. At a $60 class pack, $240 to $300 per campaign. On a free email tool. Once a month.

That is a real channel.

How to export your list from Square, Toast, or Clover

Square: Log in at squareup.com. Go to Customers, then Customer Directory. Click Export in the upper right corner. Download the CSV file.

Toast: Go to the Back of House portal. Click Guests, then Guest Book. Export to CSV. Filter for guests with an email address filled in.

Clover: Log in to app.clover.com. Navigate to Customers, then All Customers. Select Export. The file includes email, visit count, and last visit date.

Lightspeed: Go to Reports, then Customers, then Export.

Open the file in a spreadsheet. Delete rows without email addresses and any obvious test entries. What is left is your list.

What to send first

Upload the list to Mailchimp. Check their current pricing at the time you read this, but as of early 2026, the free tier covered up to 500 contacts. Essentials plans started around $13 a month for 500 contacts with higher send limits, and around $20 a month for up to 1,500 contacts.

Send this email:

Subject: Hi from [your shop name]

Two or three sentences on who you are and what you do. One sentence on what you will send and how often. One small offer for staying subscribed: 10 percent off their next visit, early access to a sale, a useful tip. A link to your site or booking page.

Under 200 words. No template. Write it like you would text someone who bought from you twice last year.

Your open rate on the first send will be higher than any email you send after it. People are curious. Use that.

What not to do

Do not wait until the list hits 1,000 addresses. Three hundred real customers is enough.

Do not mix in a bought list of contacts. That drops your open rate and gets your domain flagged as spam. Your list works because those people know you.

Do not send 600 words about what is happening at the shop this month. Nobody reads that. One offer, one update, or one tip. Done.

The Greenwood shop sent their first email three weeks after we found the list. Subject line: "10% off this week from [shop name]." Open rate: 41 percent. Revenue tracked to that send: $622.

Their monthly Facebook spend had been producing $180 in trackable revenue.

The list was already there.

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Sources

#	Source	What it backed up
1	Litmus 2024 State of Email Marketing Report	Email marketing returns $36 per dollar spent, industry average.
2	Square Customer Directory documentation	How Square stores and exports customer email addresses from receipt opt-ins.
3	Toast Guest Book export guide	How to access and export customer contact data from Toast POS.
4	Mailchimp pricing	Free tier and paid plan structure; verify current pricing before signing up.

Check current Mailchimp pricing before signing up, as plans change frequently.