How We Test New User Acquisition Channels Without Breaking ROAS

A structured user acquisition experiment using Reddit for user acquisition

As mobile apps scale, growth eventually slows.

Core channels like Meta, Google, and TikTok become more competitive, CPIs stabilize, and incremental gains get harder to unlock. At that stage, expanding into new user acquisition channels becomes necessary, but also risky.

The real question isn’t which channel to try next.

It’s how to test new user acquisition channels without damaging efficiency or breaking an acquisition system that already works.

At REPLUG, we don’t treat new channels as quick wins. We plug them into an existing user acquisition system, test them in phases, and only scale what proves real business impact.

This is the same framework we use when helping mobile apps scale beyond Meta, Google, and TikTok without sacrificing ROAS.

This article breaks down how we tested Reddit for a dating app. Not as a channel deep dive, but as a real-world example of disciplined, system-level experimentation.

Reddit is often mentioned as a promising acquisition channel, but rarely tested with real business constraints in mind

Contact us today for expert solutions to promote your app and scale through mobile marketing.

TL;DR

• New user acquisition channels (such as Reddit) must earn scale inside a system
• CPI alone is a misleading success signal
• Strong install metrics can hide weak monetization
• Targeting quality and creative fit matter more than reach
• A channel (in this case, Reddit) is only viable when CPI, conversion, and ROAS align

The Context: Why Mobile Apps Test New User Acquisition Channels

The app was already performing efficiently on its core paid UA channels. The goal wasn’t to replace what worked, but to explore a bigger scale without sacrificing profitability.

The team wanted to understand:

• Can a new channel reach CPI parity with core platforms?
• Can it drive meaningful purchase volume?
• Can it approach sustainable ROAS over time?

This is where many app teams go wrong.

They judge success too early (based on installs or CPI alone) and scale before understanding real business impact.

We didn’t.

The Framework: How REPLUG Tests New User Acquisition Channels

Instead of jumping to conclusions, we followed a phased testing framework for Reddit as a new channel to protect the acquisition system.

Phase 1: Learn the Funnel With CPI Optimization

We started by optimizing for installs to understand how users moved from click → install → early engagement.

The goal at this stage wasn’t revenue.
It was signal quality.

Over a multi-week test, we evaluated:

• click-to-install conversion
• early in-app behavior
• early signs of purchase intent

At this stage, Reddit showed healthy upper-funnel performance, with CPI aligning closely with expectations for a controlled test. On the surface, the channel looked promising.

But surface metrics are not enough.

Phase 2: Validate Intent Through Targeting Quality

Next, we tested whether intent quality could be improved.

Targeting was split into two approaches:

• keyword-based targeting
• curated community targeting built together with Reddit’s team

The difference was immediate and material.

Community-based targeting delivered multiple times higher click-to-install conversion compared to keyword targeting. This confirmed a core principle of scalable user acquisition:

Intent-driven environments outperform broad reach, even at similar scale.

At this point, Reddit was showing CPI efficiency comparable to major channels.
Still, we didn’t scale.

Phase 3: Pressure-Test Monetization With Purchase Optimization

Once install behavior was validated, we moved deeper into the funnel.

We shifted optimization toward purchase events and extended the test window to evaluate:

• install-to-purchase conversion
• CPI behavior under deeper optimization
• early ROAS signals

This phase delivered meaningful improvements.

Purchase optimization reduced CPI materially and increased install-to-purchase conversion by several multiples compared to the install-optimized phase. ROAS improved substantially as well.

However, despite these gains, the channel did not cross internal profitability thresholds when compared to core platforms, where positive ROAS is consistently achievable.

That distinction matters.

Creative Fit: Why Format Matters More Than Creative Reuse

Creatives were tested in parallel across formats.

A clear pattern emerged when we were testing Reddit for app marketing:

• static banner creatives significantly outperformed video on CPI
• banners were multiple times more efficient than video formats
• square assets performed best due to placement visibility
• repurposed video creatives from other channels did not translate automatically

This reinforced another system-level rule:

Creative performance is contextual. A creative that wins on one channel can fail entirely on another.

Creative fit matters more than creative reuse.

The Decision: When a User Acquisition Channel Hasn’t Earned Scale (Yet)

After testing across funnel stages, the conclusion was clear:

• CPI reached parity with core channels
• conversion quality improved significantly
• ROAS moved in the right direction but remained below benchmarks

So we paused.

Because Reddit hadn’t yet achieved scale within the acquisition system.

Scaling further would have increased spend without improving profitability.
That’s how acquisition systems break.

Why This Matters for App Teams

For apps testing new user acquisition channels, this kind of structured evaluation prevents wasted spend and protects long-term ROAS.

A channel like Reddit can look healthy on CPI and installs while still failing at the business level.

The takeaway isn’t “Don’t test new channels.”
It’s “Test them properly, long enough, and with the right success criteria.”

That means:

• judging channels on revenue, not installs
• comparing performance against system benchmarks
• being willing to pause without forcing scale
• treating experimentation as a controlled process, not a gamble

What This Says About REPLUG’s Approach

At REPLUG, channels are modules, not strategies.

We don’t sell traffic.
We design and protect user acquisition systems.

That means:

• every channel is evaluated against the same economic standards
• CPI, conversion, and ROAS are assessed together
• budget flows to what sustains growth, not what looks good early

This discipline is what allows apps to scale beyond their core channels without sacrificing efficiency.

Final Thought

Testing new user acquisition channels isn’t about chasing trends. It’s about knowing:

• when to push
• when to iterate
• and when to stop

That judgment is what keeps growth scalable.

👉 Thinking about expanding beyond Meta, Google, or TikTok?

We help mobile apps test and scale new user acquisition channels inside systems that protect ROAS and long-term growth. Let’s talk.