The formula, unpacked
Efficiency = CR (%) ÷ CPT ($)
CPT (cost per tap) is what an ad network charges when someone taps your ad. CR (conversion rate) is the share of store-page visitors who install. Divide them and you get installs-per-dollar pressure: a niche with 6% CR and $0.35 taps scores 17.1; a niche with 3% CR and $1.50 taps scores 2.0. The first acquires users 8.5× more efficiently before monetization even starts.
Worked example: $1,000 of ads at $0.35 CPT buys 2,857 taps; at 6% CR that's ~171 installs → $5.84 per install. Same $1,000 at $1.50 CPT and 3% CR: 667 taps, 20 installs → $50 per install. If your subscription LTV is $12, one niche prints and the other burns.
Top efficiency (cheap taps, strong CR)
- Screen recorder
- Remote control (TV/devices)
- Utility tools
- Poster & card maker
- Office suite
- VPN
- Personalization
- Travel
Medium efficiency
- PDF reader
- Document scanner
- AI assistants (crowded creative)
- Photo editors
Demand is real but competition bids up CPT — you need differentiated store creatives or higher LTV to survive.
Why utility niches win
- Intent is explicit: someone searching "screen recorder" already wants exactly that — CR soars.
- Creatives are cheap: a 15-second demo sells a tool; lifestyle apps need brand-building.
- Broad, unglamorous demand means big ad inventory at low bids.
- Caveat: efficiency attracts clones. The ratio decays as competitors bid up CPT — re-measure monthly.