What surprised us most: the cheapest registrations of the whole campaign came at the peak of scale — not before it.
The result
$306K of spend across three channels over eight months. The efficiency numbers are the ones worth looking at twice.
164,114Total registrationsfrom zero in September
53,327Peak monthly regsMarch 2026
$1.87Blended CPRall channels, full period
$1.26Best monthly CPRMarch, after consolidation
−39%CPR improvementDecember → March
65.2%Install → reg ratestable across the ramp
251,574Total installsAppsFlyer, all channels
125%Goal attainment45,223 vs 36,000 target
The brief
One job: scale signups, keep them cheap.
Zumi is an AI companion app — you make one, talk to it, feed it candy, and it grows. Freemium, with Zumi Plus at $2.99/week. The original media plan set a single job: show growth over time while keeping cost-per-registration efficient. Once AppsFlyer was firing the signup event, Meta's optimization switched from install to signup and CPR became the number that mattered. Mid-campaign, the client set a concrete target: 36,000 signups by end of March.
MoM growth in signups and installs
Keep CPR efficient while scaling spend
Switch optimization from install to signup
36,000 signups by end of March
How it landed: 45,223 signups by end of March — 125% of the target.
The move
We cut Google and TikTok, and ran Meta only.
In late February we made two structural changes at once: we ran Meta only, and inside Meta we collapsed several geo-specific campaigns into a few worldwide-targeted ones. One algorithm, one pool of signal, roughly the same weekly budget. Comparing the four weeks before to the four weeks after isolates what that did.
Pre-consolidationJan 26 – Feb 16 · 4 weeks
CPR$3.97
Spend$54,094
Installs17,467
Registrations13,623
Install → Reg78%
→
Post-consolidationFeb 23 – Mar 16 · 4 weeks
CPR$2.09
Spend$71,099
Installs44,472
Registrations33,940
Install → Reg76%
CPR−47%
CPI−48%
Installs+155%
Registrations+149%
Spend rose 31% between the two windows; installs rose 155% and registrations 149%. The extra spend explains a small fraction of that — the rest is the consolidation.
Why it worked
One big learning set, not many small ones.
Channel consolidation. Through Sep–Jan we ran the original 30/30/40 split across Meta, Google and TikTok — a hedge while we found which algorithm could deliver quality signups at volume. TikTok wound down in January; Google paused at the end of February. After that, Meta was the only channel.
Campaign consolidation. Inside Meta, several geo-specific campaigns were collapsed into a few worldwide-targeted ones — fewer campaigns competing for the same audience, more signal per campaign, less wasted learning.
Quality didn't move. Install-to-registration held at 64–80% from December through April — the highest blended rate (74.5%) came in April, after the scale peak. We were buying cheaper installs, and they registered just as well as the expensive ones.
Channel mix · $306,340 total
Meta74%$226,492
Google22%$66,496
TikTok4%$13,353
Monthly trajectory
Registrations climbed as cost kept falling.
All channels combined. February and March sit on either side of the consolidation — and March, the peak-volume month, was also the cheapest.
Monthly registrations vs. cost per registration
RegistrationsCPR ($)
Month
Spend
Meta
Google
TikTok
Installs
Regs
CR
CPI
CPR
Sep 2025
$1,181
$1,080
$100
—
1
—
—
—
—
Oct 2025
$7,849
$3,223
$4,334
$292
2,652
—
—
$2.96
—
Nov 2025
$29,209
$8,486
$15,330
$5,393
17,552
2,027
11.5%*
$1.66
—
Dec 2025
$38,163
$15,587
$15,259
$7,317
26,014
18,328
70.5%
$1.47
$2.08
Jan 2026
$55,847
$39,779
$16,068
—
33,074
24,371
73.7%
$1.69
$2.29
Feb 2026
$75,151
$59,396
$15,404
$351
73,712
47,269
64.1%
$1.02
$1.59
Mar 2026
$67,323
$67,323
—
—
73,333
53,327
72.7%
$0.92
$1.26
Apr 2026
$31,618
$31,618
—
—
25,236
18,792
74.5%
$1.25
$1.68
* November CR is understated — AppsFlyer wasn't fully tracking the signup event yet. The highlighted March row is the cheapest month.
Methodology. Zumi · AI companion app (iOS), Sep 2025 – Apr 2026, English-speaking markets. Channels: Meta, Google, TikTok; MMP: AppsFlyer. All figures pulled from the connected ad accounts and AppsFlyer. CPR = spend ÷ registrations; CPI = spend ÷ installs; CR = registrations ÷ installs.
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