International travel has bounced back, and with it, a new category of travel tech apps is quietly reshaping how people plan, connect, and move across borders. From eSIM providers to booking platforms and travel wallets, these apps are competing in a market that is expanding fast. The Asia Pacific eSIM market alone was valued at over USD 1.3 billion in 2024 and is projected to reach nearly USD 4.8 billion by 2031, growing at a Compound Annual Growth Rate (CAGR) of 20.5%. Southeast Asia is part of that momentum, with regulatory complexity and fragmented user behavior making the region both a major opportunity and a genuine challenge to execute in.
Apart from the product, what separates the apps pulling ahead is how they’ve matured their approach to mobile marketing. This is specific to how they acquire users at scale, measure what’s actually working, and protect the infrastructure that keeps growth running.
The hidden complexity of multi-market growth
Operating across dozens of markets sounds like a growth story. In practice, it means managing different user behaviors, different channel mixes, and different fraud environments, simultaneously, at scale.
Even referral programs, which are often treated as a universal growth lever, don’t behave uniformly across markets. In Malaysia, where users spread across more than eight active social platforms a month and community-driven content plays a larger role in purchase decisions, peer recommendations travel differently than in Singapore, where users spend nearly half the time on social media and tend toward more deliberate, comparison-led research before converting. Two neighboring markets, one border apart, and the referral dynamic is already meaningfully different.
When user behavior diverges that sharply, the attribution layer has to work harder. What looks like a referral conversion in one market may be traveling through an entirely different channel path in another. And the attribution infrastructure tying it all together has to be reliable everywhere, or the data that informs every growth decision starts to erode.
This is where many travel apps underestimate the stakes. Growth channels are only as strong as the measurement stack beneath them. A broken attribution flow doesn’t just obscure what’s working, but it actively misdirects spend and undermines the channels you’ve built.
When infrastructure disruption becomes a growth risk
Most travel app growth post-mortems point to the usual suspects: rising Cost Per Installs (CPIs), fraud, and channel saturation. Rarely do they mention the tools the team never thought to question. Apps that rely on third-party tools for critical functions like deep linking are exposed when those tools change or disappear, and the downstream impact lands directly on acquisition costs and conversion rates.
Most travel app growth post-mortems point to the usual suspects: rising Cost Per Installs, fraud, and channel saturation. Rarely do they mention the tools the team never thought to question.
Deep links power some of the highest-value user journeys in travel apps: referral flows, re-engagement campaigns, deferred installs. When the infrastructure behind them is disrupted through deprecation, policy changes, or attribution gaps, the effect lands directly on acquisition costs and conversion rates.
This is exactly what happened when Google announced the deprecation of Firebase Dynamic Links, forcing many apps to urgently migrate their deep linking setup mid-campaign. For travel apps where referrals drive a meaningful share of new users, that kind of forced migration is a growth continuity problem.
Building measurement infrastructure that scales
The travel apps navigating this well share a common approach: they treat attribution and measurement as a strategic layer, instead of a background function. That means consolidating tools where possible, reducing vendor dependencies, and ensuring that every user journey, especially high-value ones like referrals is tracked with precision.
This shift is already visible among eSIM platforms, where referral programs and deferred installs carry an outsized share of new users. When Firebase Dynamic Links was deprecated, the platforms that had already unified their deep linking within a single attribution stack were able to migrate on their own timeline. Those that had bolted a separate linking tool onto their measurement stack were often reacting under deadline pressure, reconciling two systems that were never designed to share data cleanly.
The broader lesson scales beyond any single tool decision. Travel apps operating across SEA and beyond are learning that sustainable growth at scale requires the same rigor applied to infrastructure as to campaigns. The channel mix will keep evolving. The markets will keep shifting. What holds it together is measurement you can trust.
April is Regional VP INSEAU at Adjust.
Featured image by Nothing Ahead.
