What Festive UA Actually Costs in India

Across roughly 4.7 million installs at around 50 India-based apps running paid campaigns on Linkrunner between May and July 2026, the median blended cost per install was just under Rs20. The middle half of those apps sat between roughly Rs8 and just under Rs40. About one in eight paid more than Rs100 for every install.

That is the ordinary, non-festive baseline. It is the number your festive plan gets measured against, and most teams have never written it down.

The festive window will move it. What follows is where the movement actually comes from, why the metric most teams watch will mislead them, and how to build a budget that survives it.

When does India's festive cost window actually open?

Festive season CPI is the cost per install an app pays during India's festive advertising window, roughly late September to mid November, when e-commerce, fintech and quick commerce compress a large share of annual ad budgets into about six weeks.

The window does not open with Diwali. In 2026 Diwali falls on Sunday 8 November, but the auction gets expensive far earlier, because the sale calendar runs ahead of the festival:

• Late September to early October. Flipkart Big Billion Days runs from roughly 23 September to 2 October, with Amazon's Great Indian Festival overlapping. This is the first real spend spike.

• Mid to late October. Navratri and Dussehra. A second wave, usually softer than the first but sustained over more days.

• 6 to 10 November. Dhanteras through Bhai Dooj, with Diwali on 8 November. Peak transaction volume for commerce and fintech apps, and the most expensive inventory of the year.

Three waves, not one. Teams that plan for a single November peak arrive at the auction six weeks late and pay for the privilege.

Why festive CPI rises

Four forces stack, and they compound rather than add.

• Auction density. Every large advertiser in the country bids at once. Your cost per install is set by whoever else wants the same impression, and during festive that is a marketplace with a nine-figure budget.

• Budget compression. Annual marketing budgets get spent in a six-week window. The same money chasing the same inventory in less time raises clearing prices.

• Creative fatigue accelerates. Frequency climbs, so creative burns out in days rather than weeks. Serving a fatigued ad into an expensive auction is the fastest way to waste festive budget. Our guide to creative fatigue detection and refresh cycles covers the diagnostics.

• Attention shifts. Users are in shopping apps, not yours. Impressions are still available; intent is not.

If your app is not a shopping app, the first three still apply. You pay the festive tax whether or not you get the festive demand. This is the single most important thing for non-commerce apps to understand before they commit budget.

The metric that misleads everyone

Here is what makes festive budgeting genuinely hard: CPI is a poor guide to whether a festive campaign worked, because install volume and install quality move in opposite directions.

Install counts rise during festive. Ad networks are optimising towards installs, inventory is abundant, and curiosity-driven downloads spike. So CPI can look flat, or even improve. Meanwhile the share of those installs that actually activate falls, because the people installing are browsing, not committing.

The Linkrunner data shows how large that gap gets even outside a festive window.

Across the same set of around 50 India apps, the median activation rate, meaning the share of installs that reached the app's own defined onboarding event, was around 67 per cent. But the spread was enormous, and the spread is where the money goes:

Read the right-hand column. For apps with strong activation, cost per activated user is roughly 1.2 times CPI. For apps with weak activation, it is close to three times CPI. Same metric, wildly different meaning.

Cost per activated user is total ad spend divided by users who completed your activation event, rather than by users who merely installed. It is the number that tells you whether a festive campaign bought customers or bought downloads.

Ten of the 48 apps in this sample sat below 50 per cent activation, and between them they held around a fifth of all the ad spend. That is a meaningful amount of money flowing towards installs that never became users, in an ordinary month with no festive pressure on it.

Festive pushes every app down its own activation curve. If you are already in the bottom half, festive is where the gap between what you think you are paying and what you are actually paying gets expensive.

Methodology: figures are drawn from Linkrunner projects with a connected ad network account and INR as base currency, May to July 2026. Blended CPI is total connected ad spend divided by total installs, which includes organic installs, so it understates paid-only CPI. Activation is each project's own defined onboarding event, so definitions vary by app. Use these as bands, not targets.

How to budget without overcommitting

Set your walk-away number before the window opens. Not your target CPI. Your maximum tolerable cost per activated user, agreed with whoever owns the budget. During festive nobody has time to negotiate this, so it gets decided by whoever is most optimistic at 11pm.

Use reserve-and-release rather than front-loading. Split the festive budget into three tranches tied to the three waves. Release each one only after the previous wave's activation numbers come in. Teams that commit everything in September have no room to respond when Diwali week turns out to be cheaper or dearer than expected.

Decide honestly whether to bid through the peak. A rough guide:

• Bid through it if festive genuinely drives your transactions: commerce, quick commerce, payments, gifting, travel, gaming top-ups.

• Bid the shoulders if you see moderate lift: content, social, edtech. Buy the cheaper weeks either side and let the marketplaces fight over Diwali week.

• Sit it out if festive drives no demand for you at all. Spending your annual peak budget in your least efficient month is a choice, not an obligation. Our guide to reducing mobile app CAC without cutting quality covers where that budget goes instead.

Hold a genuine reserve. Around 15 to 20 per cent of the festive budget, unallocated, released only against evidence. This is what lets you scale the one thing that is working on 7 November rather than watching it run out of budget.

What to measure so next year is cheaper

Most teams finish festive with a spend number and a vague memory. The teams that get cheaper every year capture three cuts, weekly, during the window:

1. Cost per activated user by channel and by week. Not CPI. The activated number, split by which of the three waves it came from.

2. Activation rate by acquisition week. This is your early warning. When it drops, your effective cost is rising even if CPI looks stable.

3. Revenue by install week, tracked for at least 30 days after. Festive cohorts and January cohorts behave differently, and you cannot see that from a November dashboard.

The second and third only work if you tag cohorts by festive week before the window opens. Doing it retrospectively means reconstructing dates from raw exports in December, which is how this task quietly never happens.

This is where having installs, activation events and revenue joined in one place stops being a reporting convenience and becomes the difference between planning next year from evidence or from memory. Linkrunner holds those three together by cohort, so the question "what did this window actually cost us per real customer" has an answer in November rather than a research project in January.

Before you commit the budget

Write down your baseline now, in August. Your current CPI, your current activation rate, your current cost per activated user. Three numbers, one line in a document.

Without them, every festive figure you see in November will be uninterpretable, because you will have nothing to compare it against. With them, you will know within a week of Big Billion Days whether the auction is behaving normally for you, and you will still have time to act.

If you want the full sequence for the 90 days before Diwali, including what to freeze and when, that is covered separately. If you want to make sure your measurement will survive the volume spike, start with the weekly attribution audit checklist and run it before spend climbs rather than after.

And if you would like to see what your own festive cohorts actually cost per activated user rather than per install, request a demo and we will walk through the cuts on your data.

FAQ

How much do app install costs rise during Diwali in India?

It varies by category and by how much of your inventory overlaps with e-commerce. The more useful framing is that costs start climbing in late September with Big Billion Days rather than in November, and that your effective cost rises faster than your CPI because activation rates fall. Establish your own pre-festive baseline in August so you can measure the delta rather than guess it.

When do festive CPMs start climbing?

Typically from mid to late September, ahead of Flipkart Big Billion Days and Amazon's Great Indian Festival. In 2026 that means the last week of September, roughly six weeks before Diwali on 8 November.

Why does my CPI look stable while my CAC goes up?

Because CPI counts installs and CAC counts customers. During festive, install volume rises faster than install quality, so the two diverge. In our India sample, apps in the bottom activation quartile paid close to three times their CPI for each activated user, against roughly 1.2 times for the strongest quartile.

Should small apps advertise during the festive season at all?

Only if festive drives real demand for your category. If it does not, you are paying peak prices for off-peak intent. Bidding the shoulder weeks either side of the sale events, or redirecting the budget to a quieter month, is often the better return.

How long do elevated costs stay high after Diwali?

Costs ease through mid to late November as marketplace budgets exhaust, but the more important post-festive effect is on retention rather than cost. Festive-acquired cohorts usually retain worse than your baseline, which shows up in December and January, not in your festive dashboard.