The cheapest revenue most businesses can find is a past customer who was happy and simply never heard from them again. Winning those customers back takes four steps: sort the list by value and timing, check who you have consent to message, send a check-in that is genuinely useful, and measure the result against a small group you leave alone. This guide walks through each one.
Why past customers are worth the effort
A past customer already knows your work, trusts you enough to have paid once, and is in your records. Selling to them costs a fraction of finding a stranger, and they tend to decide faster.
Yet most owner-led businesses never measure how many customers come back. Ask an owner what share of last year's buyers bought again this year and the usual answer is a guess. The first step in any retention effort is replacing that guess with a number.
Step 1: Build and sort the list
Export every customer from the last three years with these fields, as far as your records allow:
- name and contact details
- date of last purchase
- what they bought, and its value
- total spent with you
- whether there was a complaint or unresolved issue
- how and when they gave permission to be contacted
Then sort them into groups that call for different messages:
| Group | Who | Likely message |
|---|---|---|
| Due | Bought something that needs attention at a known interval | A timed service or renewal reminder |
| Related | Bought one thing that naturally leads to another | A short note about the related service |
| Lapsed high-value | Spent well, then went quiet | A personal call or note |
| Unhappy | Had an unresolved issue | A call to fix it, never a promotion |
The "unhappy" group comes first, and it gets a person, not a campaign. Fixing an old problem often wins a customer back on its own.
Step 2: Check consent before anything is sent
Canada's anti-spam legislation, known as CASL, applies to commercial electronic messages, which include email and text messages that encourage someone to buy. ISED's guidance explains that CASL has been in force since 2014 and that it focuses on those commercial messages.
In practice, that means:
- Know your consent basis for each contact. Express consent is clearest. Implied consent can arise in some situations, such as a recent purchase, but it is limited in time and scope. Read the official guidance for the details.
- Identify yourself and offer an easy way to unsubscribe in every commercial message.
- Honour opt-outs promptly and keep a record.
- Keep personal information for its stated purpose. Under PIPEDA, the federal private-sector privacy law, organisations must handle personal information appropriately; some provinces have their own similar laws.
This is general information, not legal advice. If your list is large or your consent records are patchy, have a lawyer review your approach before you send anything.
Step 3: Time the check-in and make it useful
The right moment to contact a past customer is when they are likely to need you, not when you have a slow week.
- Service intervals. If your work needs attention every year, contact customers a few weeks before the anniversary.
- Seasons. Get in touch ahead of the season when the need arises, not during the rush.
- Life of the product. If what you sold wears out or goes out of date, a note before that point is helpful, not pushy.
- After a good outcome. A customer whose job finished well last week is the right person to ask for a referral.
A useful message answers a question the customer probably has. A template you can adapt:
Hi [First name], this is [Your name] at [Business name]. It's been about [time period] since we [what you did]. Around now, [the common issue or need]. If you'd like us to [specific service], reply here or call [phone]. If you'd rather not hear from us, reply STOP and we won't contact you again.
Step 4: Measure against a held-back group
Without a comparison, you can't tell whether the check-in worked or whether the season was just busy. Before sending, set aside a small share of each group, perhaps one in ten, and don't contact them.
After six to eight weeks, compare:
- Repeat-purchase rate in the contacted group and the held-back group.
- Revenue per contacted customer.
- Opt-outs, to make sure the message isn't annoying people.
A worked example
A business has 900 consented past customers. It holds back 90 and contacts 810. After eight weeks, 6% of the contacted group have bought again, against 2% of the held-back group. The four-point gap, applied to 810 customers, is about 32 extra sales. At a $700 average, that is roughly $22,400 attributable to the check-in, for the cost of writing it and answering the replies.
Who should send the message
A message from a named person reads differently from one signed by "the team". Where you can, have the check-in come from the person the customer actually dealt with, or from the owner. Replies should go to someone who can answer questions and book work on the spot. A check-in that produces replies nobody handles for three days does more harm than no check-in at all.
Common mistakes
- Sending a discount to everyone. It trains customers to wait for offers and cuts margin on people who would have bought anyway.
- Ignoring the unhappy group. A promotion sent to someone with an open complaint makes things worse.
- Messaging without consent records. It risks penalties and damages your reputation.
- Measuring without a control. Busy seasons make every campaign look good.
- Sending once and stopping. A retention routine is a calendar, not a single blast.
How this fits in a revenue sprint
In a sprint, the retention workstream starts around day 45, after the pricing and pipeline work is under way, because repeat revenue takes longer to build. The consent audit and repeat-rate baseline come first, then the check-in calendar, then referrals and account plans for larger clients.
To look at your customer list together, call, text or email.
Frequently asked questions
Can we text or email every customer we have ever served?
Not automatically. Canada's anti-spam legislation covers commercial email and text messages, and you need consent, express or in some cases implied, to send them. Check the official guidance and get legal advice if unsure.
Is a phone call different from a text?
Phone calls are covered by different rules from email and text. Whatever the channel, respect anyone who asks not to be contacted, and check the rules that apply to your type of outreach.
What should the first message say?
Something useful to the customer: a service reminder, a timely check, or an answer to a question they are likely to have. A plain discount with no reason tends to work less well.
How many past customers usually come back?
It varies too much by business to give a figure. Measure your own rate before and after, against a small group you don't contact, and you will know.