Direct Mail That Drove Real Enrollments
A/B-tested postcards that turned mailboxes into phone calls for a solar buyback program, delivering 5x response lift and 33% call-to-sale conversion.
The Challenge
An energy client needed to add a high-intent offline touch to amplify their existing Google Ads and SEO efforts. The goal was to drive enrollments for their Solar Buyback program by reaching homeowners in Texas markets with high solar density—people who had already shown interest by visiting the website.
Goals
- Add high-intent offline touchpoint to complement digital campaigns
- Drive Solar Buyback program enrollments
- Reach warm audiences who had already visited the website
- Test creative concepts to optimize response rates
The Strategy
Approach
We implemented a direct mail retargeting campaign that targeted website visitors with personalized postcards. The approach combined precise geographic targeting with A/B creative testing to maximize response rates while keeping costs manageable.
Key Tactics
- Segmented Texas ZIP codes by solar density and historical response propensity
- A/B tested two postcard creative concepts to identify the winner
- Used urgency positioning around unique 'true 1:1 buyback rates' offer
- Coordinated messaging across digital and direct mail channels
- Implemented full-funnel tracking with call attribution and QR codes
The Results
The campaign proved direct mail retargeting as a net-positive supplemental channel for driving high-intent phone activity, with measurable enrollments and a clear creative winner.
The Campaign in Detail
When the energy client approached us, they had a strong digital presence with Google Ads and SEO driving consistent traffic to their Solar Buyback landing pages. But they were leaving money on the table—website visitors who showed interest but didn't convert were simply disappearing into the digital void.
Direct mail retargeting offered a solution: reach those same visitors in their physical mailbox within 2-3 days of their site visit, while the brand and offer were still fresh in their minds.
Creative Testing: Finding What Works
We didn't assume we knew what would resonate. Instead, we ran a structured A/B test with two distinct creative concepts:
- Concept A: A bold, attention-grabbing design with distinctive imagery
- Concept B: A family-focused approach with lifestyle imagery
The results weren't even close. Concept A delivered approximately 1.0% response rate compared to just 0.2% for Concept B—a 5x difference that would have been impossible to predict without testing.
Targeting Strategy
Not all website visitors are created equal. We layered multiple targeting criteria to focus spend on the highest-potential prospects:
- Geographic focus: Texas ZIP codes with documented solar density
- Behavioral signals: Website visitors who engaged with Solar Buyback content
- Historical propensity: Areas with proven response rates from previous campaigns
Measurement Stack
Attribution is everything in direct mail. We implemented a comprehensive tracking system:
- Direct mail platform: Send/response tracking with daily reporting
- Call tracking: Source-level attribution for phone conversions
- GA4 integration: QR code scans and landing page behavior
This allowed us to see not just who responded, but how they responded and whether they converted—critical data for optimizing future campaigns.
The Bottom Line
With a typical monthly budget of $1,200-$1,500, the campaign delivered measurable enrollments and proved direct mail retargeting as a viable, net-positive channel. The key insight: it works best as a supplement to strong digital campaigns, not a replacement for them.
For businesses with website traffic and sufficient margins, direct mail retargeting offers something digital channels can't: a physical touchpoint that cuts through the noise and reaches prospects where digital ads can't follow.
Key Insights
- Direct mail proved net-positive as a supplemental channel for high-intent phone activity, with measurable enrollments and clear creative winner.
- Best use is scaled carefully alongside brand and search campaigns, not as a primary driver.
- Creative testing is critical—the winning concept delivered 5x the response rate of the alternative.
- The speed of retargeting (2-3 days from site visit to mailbox) keeps the brand fresh while interest is high.
