Most solar installers can't say which marketing dollar produced which install. Here's how per-homeowner QR tracking on letters fixes that.
Ask most solar business owners what their last marketing campaign returned and you'll get a shrug, a guess, or a number from the ad platform that doesn't match the install calendar.
That's not a discipline problem. It's a measurement problem. Most solar marketing is built on channels that report activity (impressions, clicks, "leads") rather than people. And activity doesn't pay wages.
The real cost of "we think it's working"
When you can't tie spend to a specific home, three things happen:
- You keep paying for channels that don't convert because the dashboard looks busy.
- You cut channels that do convert because their results arrive weeks later through a phone call nobody tagged.
- You judge campaigns on the wrong number. A high click-through rate means nothing if none of those clicks became a site inspection.
The only metric that matters for an installer is cost per install: total campaign spend divided by systems actually installed from that campaign. Everything else is a proxy.
Why letters have always been hard to measure (and why that's changed)
The old objection to direct mail was fair: you sent 5,000 flyers, the phone rang a bit more, and you had no idea who had read what. Response tracking relied on a homeowner saying "I got your letter" on the phone, which most never do.
Personalised QR codes change that. Instead of one generic code printed on every piece, each letter carries a QR code unique to that household. When the homeowner scans it, the scan is tied to that property's address, not just to "the campaign".
That turns an anonymous mail drop into a list of addresses where a homeowner has just raised their hand.
One done-for-you service: list, letter, tracking
Stash Direct Mail handles the whole campaign, start to finish:
- We generate your target database. Homeowners whose properties have no solar panels, or solar owners if you're selling batteries. Or you can use your own prospect list.
- We send your letter. Our mail house personalises and posts the direct mail letter you already use. No redesign, no printer to manage.
- We track every response. Each letter carries a QR code unique to that household. When a homeowner scans, we alert you with the property address so your team can follow up while interest is high.
- You match scans to quotes and installs. That gives you a real cost per scan, cost per quote and cost per install for every campaign.
Less waste before a single letter is posted
Most wasted spend is wasted audience. Every Stash Direct Mail list is filtered so you only pay to reach people who can say yes:
- Homeowners only, never tenants
- Houses only, never apartments
- No solar on the roof for system sales, or existing solar for battery sales
And we can time the send to the moments homeowners are most likely to act: new owners who've just moved into a home without solar, systems more than 10 years old, and areas recently hit by storms.
What to measure, and what to ignore
| Metric | What it tells you | Use it to |
|---|---|---|
| Scan rate | How many homeowners engaged with the letter | Compare lists, offers and letter versions |
| Scan-to-quote rate | How well your follow-up converts interest | Coach your sales team and fix response speed |
| Quote-to-install rate | How competitive your offer and pricing are | Adjust offer, finance or battery bundle |
| Cost per install | Whether the campaign made money | Decide whether to scale, change or stop |
A low response rate isn't automatically a failure. If 1 in 200 letters produces a scan and 1 in 5 scans becomes a $12,000 solar-and-battery install, the maths can work comfortably. You can only know that if every response is tied back to the letter that caused it.
A simple test you can run this quarter
- Pick one service area and one offer.
- Mail a defined list with personalised QR codes.
- Follow up every scanned address within 24 hours.
- After 60 days, divide total spend by installs.
If the number beats your current cost per install from paid social or bought leads, you've found budget worth moving.
The bottom line
You don't need a bigger budget. You need to stop paying to reach the wrong people, and know which part of the budget is working. Stash Direct Mail does both, done for you: a qualified homeowner list, your letter in their hands, and a QR code that alerts you to every address that responds.
