Every trade and service business I look at has the same asset sitting untouched in its job management system: a list of people who have already paid it money, let it into their home, and were happy enough not to complain.
And in most cases the business has never contacted a single one of them again.
Meanwhile the same owner is paying for Google Ads clicks from strangers, competing on price against three other quotes, and wondering why the cost of a lead keeps climbing. It's the strangest allocation of effort in small business marketing, and it's completely standard.
Why the list beats everything else you're doing
Cold acquisition means paying to reach someone who doesn't know you, doesn't trust you, and is comparing you to whoever else showed up in the results. That's a real channel and it works — but it starts from zero on every dimension that matters.
A past customer starts from the opposite position. They know your name. They know whether your bloke turned up when he said he would. They've already made the hardest decision a customer makes, which is letting an unfamiliar trade business into their house. The friction that costs you money in paid acquisition — trust, proof, comparison shopping — has already been paid for once.
The contrast in the numbers is stark. When we built the outbound engine for Maslec Electrical, the cold campaign reached around thirty strata and owners' corporation managers a week and produced a reply rate of about four per cent. That's a genuinely good result for cold outreach into a hard-to-reach segment, and it won real contracts. But it took thirty contacts a week, every week, to get there. A message to people who have already had you out and were pleased with the job does not perform anywhere near four per cent. It doesn't need thirty a week either.
The reason to make contact is the whole game
Reactivation fails when the message is "just checking in" or, worse, "here's 10% off." Both signal that you want something. Neither gives the customer a reason to act today.
What works is a reason that comes from the job itself, and every trade has them sitting in plain sight. Smoke alarms need testing. Split systems need servicing before the first hot week. Switchboards installed a decade ago are worth a look. Hot water systems have a life expectancy the customer doesn't know. Safety switches should be tested. A gutter cleaned last autumn will need it again. Warranty periods expire. Compliance certificates lapse.
None of these are marketing messages in disguise. They're genuinely useful, they're specific to the work you did, and they're timed. "We installed your unit in March 2023 — it's due for a service before summer, and it's usually about $180" is a message a customer is glad to receive. "Hi, hope you're well, we're running a special" is one they delete.
This is also the on-ramp to something more durable. A one-off reactivation is a spike; a scheduled annual service is revenue you can plan around, and turning good one-off jobs into recurring ones is a strategy in its own right — worked through properly in how to build recurring revenue in a service business.
The rules you can't ignore
Before you export anything and start sending, know the law. Marketing emails and SMS to Australian addresses are governed by the Spam Act 2003, and the ACMA is clear about what compliance requires.
You need consent, which can be express or inferred. Express consent is where someone knowingly accepts that they'll receive marketing from you — a form, a ticked box, a conversation on the phone or face to face. Inferred consent can exist where a person knowingly and directly gave you their address and it's reasonable to believe they'd expect marketing from you, usually because there's a provable, ongoing relationship and the marketing is directly related to it.
Here's the trap. The ACMA states plainly that inferred consent does not cover sending messages after someone has just bought something from your business. A single job does not, on its own, hand you a mailing list. And under the Spam Act, the burden of proof sits with you — if it's questioned, you have to demonstrate you had consent.
The other requirements are simple but non-negotiable. Every commercial message must accurately identify you or your business, using your correct legal name, or your name and ABN, with correct contact details that stay accurate for at least 30 days after sending. Every message must carry a clear unsubscribe option that costs nothing, doesn't require the person to log in or create an account or hand over extra personal information, stays functional for at least 30 days, and is honoured within five working days. If someone else sends on your behalf, none of that becomes their problem — you still need the consent, and the message must still identify you as the business that authorised it.
And the one that surprises people most: you cannot send an electronic message asking for consent, because that message is itself a marketing message. There's no legal way to email your way out of not having asked.
Gold nugget. Capture express consent at the point of service, on the job, while you're standing in front of the customer — because you can't go back and ask by email later. Add one line to the job sheet or the invoice sign-off: "Would you like a reminder when your next service is due?" with a tick box and a note of who asked and when. It takes four seconds, it's the strongest form of consent there is, and it converts a customer record into a permanently contactable one. Do it for every job from today and in twelve months you'll own an asset your competitors can't buy. The ACMA expects you to keep a record of who gave consent, when, and how — so build the record into the paperwork rather than trying to reconstruct it later.
For phone calls the regime is different again — the Do Not Call Register rules apply to telemarketing, and they're worth checking before anyone starts working through a list by phone.
How to actually run it
Start smaller than you think. Export everyone you've done work for in the last three years where you have proper consent, and sort by the job type with the clearest recurring need. Take the first fifty.
Send one message with one specific, timed reason to act, a real price or price range, and one way to respond. Then — and this is the part most businesses skip — make sure someone is ready to answer when the replies land. A reactivation campaign that generates fifteen enquiries into an unwatched inbox is worse than no campaign, because you've spent the goodwill and returned nothing. How fast you reply decides whether you win the job applies to warm leads exactly as much as cold ones. Arguably more: a past customer who gets ignored doesn't just not book, they revise their opinion of you.
Then make it a rhythm rather than an event. One list, one reason, once a month or once a quarter, tied to something seasonal — heating before winter, cooling before summer, safety checks at the start of the financial year. Quarterly beats annual, and monthly beats quarterly, provided each message earns its place.
While you're in there, the same conversation is the best time to ask for a review. A customer you've just helped for the second time is the easiest review you'll ever get, and reviews compound into the visibility that brings you new customers — the mechanics of which are in how to get more Google reviews for your trade business.
The uncomfortable bit
If you've read this far and thought "I don't have a list," that's the finding. It means the customer data is scattered across a phone, a shoebox of invoices, a bookkeeper's spreadsheet and someone's memory. Building it is unglamorous work and it is worth more than the next thing you were going to spend on advertising, because every job you've ever done is either a future customer or a wasted acquisition cost, and right now it's the second one by default.
If you're spending money on new leads while an entire pipeline of warm ones goes untouched, that's a gap worth closing before you increase the ad budget. It's one of the things we look at in the Business Health Check: a fixed-price review of your numbers and your lead engine, end to end, with a written plan of what to fix first. Or start with the free 5-minute scorecard if you'd rather see where you stand first.