Database reactivation with consent: winning back past customers by message
Every trade business owns a list of past customers it never writes to. That list is worth more than the next ad campaign, but in Germany you cannot simply text it. This article covers why the old list wins, the consent rules in one paragraph, and a six-touch schedule that stops when the customer says so.
An electrical contractor with nine staff has been trading for fourteen years. Its invoicing software holds about 600 customer records. Perhaps a third of those people have had work done in the last two years. The rest had a fuse board replaced in 2019, a garden socket fitted in 2021, a heat pump wired in 2023, and have not heard from the firm since. Every one of them will need an electrician again, and right now they would have to search Google to remember the name.
The owner, meanwhile, is looking at a quote for Google Ads. The plan is to find new customers in the same postcodes where 400 past customers already live.
That is the situation at almost every owner-run trade business I have looked at. The old list is the cheapest source of work the firm has, and it sits untouched because nobody knows what is allowed and nobody has time to find out.
Why the old list beats new ads
A past customer already knows your van, your prices and whether you clean up after yourself. There is no ad auction to win. The only thing missing is a reason to call you this month rather than eventually.
The numbers on follow-up show how much of this work businesses leave on the table. Velocify, in a 2014 secret-shopper study of sales lead response, found that the average sales team made 1.45 call attempts per lead before giving up, and that 13 percent of enquirers never heard from anyone at all. An earlier Velocify analysis from 2013, covering about 3.5 million leads across more than 400 companies, found that 93 percent of the leads that ever converted had been reached by the sixth contact attempt. Both figures come from vendor platform data with a stated methodology, and neither is specific to trades. But the shape of the finding matches what owners describe. One message goes out, nothing comes back, and the list goes back in the drawer.
Six messages are not magic. Most businesses stop after one, and the work that converts on the third or fifth contact goes to whoever is still writing.
The German consent rules in one paragraph
Here is the part that stops most owners. In Germany, section 7 of the Unfair Competition Act (UWG) treats any promotional message by email, SMS or messaging app as requiring the recipient's prior express consent. Cold SMS to a list you scraped or bought is out, full stop. So is texting a past customer who never agreed to receive messages from you, even though they were once happy to pay you. There is one exception, in section 7(3), for existing customers. If you collected the email address in connection with a sale, use it only for your own similar services, the customer has not objected, and you told them clearly at the time of collection and in every message that they can object at any time, you may write to them without a separate consent. That exception was written with email in mind and courts have been cautious about stretching it, so treat it as a fallback for email only. For SMS and WhatsApp, get consent. On top of the UWG, the GDPR requires that your privacy notice says you contact past customers this way, and that any tool you use to send the messages is covered by a data processing agreement. I am not a lawyer. An hour with one who knows the UWG costs less than a single warning letter.
Getting consent without a campaign
The practical question is how a nine-person electrical firm gets 400 past customers to opt in. It does not. It gets consent from every customer from now on, and it uses a permitted channel to ask the old ones.
For new and current jobs, add a line to the order confirmation and to the completion report: "We would like to contact you occasionally by email or text about our services and reminders. You can withdraw this at any time." A tick box, not pre-ticked, or a signature. Ask again at handover, in person, because a customer who has just watched you do good work says yes.
For the old list, a letter is still allowed. It costs postage and it feels old-fashioned, and it is the one channel that reaches 400 people you have no consent to text. A short letter that reminds them who you are, mentions one useful service, and gives them a way to opt in to messages does two jobs at once. Business customers are a little easier. For a landlord or a facilities manager who buys from you regularly, the existing-customer exception is on firmer ground.
Once consent is in place, the messaging can start.
A six-touch schedule
The schedule below assumes a customer who has given consent and has not been in touch for more than a year. Every message has one job and one reason. The sequence stops the moment the customer replies or asks to be left alone; there is no exception to that.
Day 0. A short hello with a reason to write now. For the electrical firm in early autumn: "Hello Ms Example, this is Muster Elektrik. We fitted your fuse board a few years ago. Before the heating season we are offering a check of older installations in your area. Would that be useful? Reply STOP at any time to end these messages."
Day 3. A follow-up with a concrete slot, not a repeat of the first message. "We are in your street on Thursday afternoon, if you would like us to look in."
Day 7. A different reason. Something the firm now offers that it did not offer when the customer last called, such as a wallbox installation or a PV connection.
Day 14. A question rather than an offer. "Is there anything in the house that has been on the list for a while? A socket, a light, a cable that runs where it should not?"
Day 30. A quiet reminder that the firm exists, with the phone number and nothing else.
Day 45. The last message. "This is our last note for now. If we can help at any point, you have our number. Thank you for being a customer." And then silence until the customer writes.
Six touches across six weeks is unhurried. Nobody receives two messages in the same week, and every message would be reasonable on its own. That matters because the same customer who is glad of a reminder in week one is annoyed by the fourth message in ten days.
Doing it by hand, and doing it automatically
A firm with 100 consented customers can run this from a phone and a spreadsheet: a column for the date of the last job, a column for the next touch, six templates. The writing is easy. Remembering day 14 for 100 people while running nine electricians is the hard part.
The database reactivation employee is the automated version of this schedule. It reads the customer list, writes only to people with recorded consent, sends the six touches on the timetable above, stops on a reply or a STOP, and passes replies to the office as a booking or a callback. Because the list already exists, it is the first employee in the sequence that brings in work, and the fastest way to see whether the system pays for itself. The calculator will tell you what your own list is likely worth.
The electrical firm with 600 records does not need Google Ads this autumn. It needs to write to the 400 people who already trust it, in a way it is allowed to, and to keep writing until they answer.