David Didau: The Learning Spy
Investor Due Diligence Report
The Learning Spy Substack is a sharp, provocative dispatch from the front lines of education, where ideas are tested, myths are challenged, and nothing is taken for granted.
7K
700 paid
N/A
Pricing
$3.5/mo
$30/yr annual option
$2K
700 paid subs
$2K/mo – $2K/mo(±0%)
6.3
50.3
0.81%
(comments + likes) / subscribers
Weekly
1.3 posts/week
64/100
Consistent (~6.2d avg)
| Newsletter | Subscribers | Weekly Growth | Price | Platform |
|---|---|---|---|---|
| AlgoMaster Newsletter | 141K | +0.4% | $29/mo | substack |
| Uncharted Territories | 124K | +0.4% | $10/mo | substack |
| All About Psychology | 104K | +1.1% | $5/mo | substack |
| The Shit No One Tells You About Writing | 84K | N/A | $10/mo | substack |
| Month | Subscribers | Est. Revenue | Change |
|---|---|---|---|
| Feb 2026 | 6K | $1,512 | — |
| Mar 2026 | 7K | $1,764 | +16.7% |
Platform Dependency
Hosted on substack subdomain
Publishing Consistency
Variable publishing frequency
Key Person
Single-author publication — key-person dependency
Revenue Model
Active paid subscription tier
Subscriber threshold
7K subscribers — above the 1K category median for first paid tier
Has paid tier
Active paid subscription offering
Peer monetization
100% of 66 similar-size peers in Education have paid tiers
Pricing position
$3.5/mo vs $5/mo category median (493 newsletters)
| Date | Monthly | Annual |
|---|---|---|
| Mar 2026 | $4 | $30 |
Disclaimer: This report is generated automatically based on publicly available data and proprietary estimation models. Estimated subscriber counts are derived from engagement patterns and should be verified through direct disclosure. Revenue estimates are based on known pricing and estimated paid subscriber counts. This report is for informational purposes only and should not be the sole basis for investment decisions.
Score based on available components only.
| Component | Score | Weight |
|---|---|---|
| Engagement Rate | 65/100 | 30% |
| Paid Subscriber Ratio | 90/100 | 25% |
| Publishing Consistency | 36/100 | 10% |
| 3Blue1Brown mailing list | 69K | +2.3% | Free | substack |