Some products reveal user value quickly. A player installs, starts spending during the first week, and the media buying team gets an early read on whether the campaign is moving in the right direction.
Other products need more time. Revenue may continue building well after D7, especially when retention is strong or ad monetization plays a large role. In that setup, an early purchase gives the source only part of the picture.
Unity has been expanding ROAS optimization around that longer user history. D28 IAP ROAS launched earlier in 2026, followed by D28 Ad Revenue and Hybrid ROAS campaigns. Unity positions D7 and D28 as complementary windows: one captures early value, while the other gives the model more time to recognize users whose value develops later.
For a media buyer, the change goes much further than selecting D28 in the dashboard. The decision starts with the product.
Start With the Revenue Curve
ROCKAPP buyers look at the funnel before choosing an optimization window. The key question is simple: when does the product actually start showing meaningful user value?
A game where most revenue appears during the first week gives D7 plenty to work with. The feedback arrives quickly, and the campaign can build around users who monetize early. A product with a longer payback period creates a different picture. If a meaningful share of revenue appears after the first week, D28 can include users that would look much less valuable inside an early cohort.
Monetization changes the answer as well. An IAP-heavy game produces one revenue curve, while a product driven by advertising may build value through continued activity over time. Hybrid products add both streams to the same user history. Unity now supports D28 optimization across IAP, Ad Revenue, and Hybrid ROAS, so the optimization setup can follow the way the product actually earns revenue.
For the media buying team, that makes product analysis part of campaign setup. The window should reflect the real revenue curve rather than the newest option available in the source.
D7 and D28 See Value at Different Times
A player who spends heavily on day three gives the algorithm a clear early signal. Another may stay active for two weeks before becoming valuable.
D7 naturally gives more weight to the first type of user. D28 has room to recognize the second.
Unity’s own comparative analysis shows how different those cohorts can be. According to Unity, only 38% of users who convert with IAP by D28 spend during the first week. In other words, a large share of valuable D28 users produces little early purchase signal.
The Homa case gives a practical example. Homa ran D28 IAP ROAS alongside D7 for All in Hole. Unity reported 14% higher D28 ARPU and 63% higher D28 retention for the D28 setup compared with the D7 campaigns in the analysis. These are results from one advertiser rather than a universal benchmark, but they show why a longer cohort can change which users the campaign finds.
A buyer therefore has to understand what kind of value the campaign is trying to capture. If most useful revenue already appears by D7, the shorter window gives the team a faster read. When the product continues monetizing strongly after that point, D28 can give the model a more complete view of the audience.
Data Quality Becomes Part of Media Buying
A longer optimization window also makes event setup more important.
Once the campaign starts learning from a larger part of the user journey, the media buying team needs confidence that the source is receiving the right product signals. Unity recommends passing post-install data such as sessions, purchase events, ad revenue, and milestone activity through the MMP. Its documentation also recommends sharing the full set of available post-install events because additional data can improve campaign performance.
For buyers, this moves integration quality closer to everyday campaign work.
Purchase data needs the correct event mapping. Ad revenue should reach the source through the appropriate revenue event. Unity specifically warns that incorrect mapping can interfere with optimization, particularly when ad revenue is passed as an IAP event through an incompatible setup.
The practical question becomes whether the source sees the same user journey that the product team sees internally. A longer window gives the algorithm more history, so gaps in that history matter more.
Before launching D28, ROCKAPP buyers need a clear view of the event setup as well as the revenue curve. Otherwise, the team may spend several weeks evaluating a campaign built on an incomplete signal.
D28 Changes the Feedback Loop
One detail matters here: D28 optimization does not equal a 28-day Learning phase.
Unity currently uses D7-matured signals to determine Learning completion for D28 campaigns. D28 IAP requires at least 75 unique D7 purchasers. D28 Ad Revenue uses at least 1,000 installs and positive D7 ad revenue, while D28 Hybrid also relies on D7-matured revenue and purchaser thresholds.
The media buying team still works with a longer evaluation cycle because the metric the campaign is built around takes more time to mature.
Delivery starts immediately. CPI and early conversion can tell the team whether the campaign is behaving normally. D28 ROAS answers a different question: how much value that cohort creates over the full optimization window.
That distinction changes day-to-day decision-making. A buyer can act on an obvious delivery issue during the first week, while the mature value of the cohort still needs time. Large campaign changes made too close together can also make later D28 results harder to interpret because several variables have moved before the original cohort matured.
ROCKAPP buyers see the longer feedback cycle as one of the main risks to evaluate before launch. The campaign needs enough budget to gather useful data while the team waits for the metric that actually matters.
Check Signal Volume Before Choosing the Window
A long monetization curve alone does not make D28 the automatic choice. The product also needs enough usable signal.
A large game with steady purchase volume can give the source many examples of valuable D28 users. A smaller product may have a long payback period and still generate very few mature purchasers in each cohort. In that case, the window is longer while the amount of useful data remains limited.
ROCKAPP buyers therefore look at expected cohort volume before choosing the campaign setup. They estimate how much data the source will see at D7 and how much additional value appears by D28.
Unity’s own Learning requirements reflect the same concern. Each ROAS campaign type needs a minimum amount of installs, revenue, or purchasers before it moves from Learning to Live.
For agency work, this is especially important when budgets are limited. Splitting spend across several optimization strategies can leave each campaign with too little signal to produce a useful answer.
The theoretically best window on paper still needs enough traffic behind it to work in practice.
When D7 and D28 Run Side by Side
Unity recommends running D7 and D28 IAP campaigns together where both early and long-term value matter. The two windows can reach different user cohorts, giving the advertiser a way to capture both parts of the revenue curve. That setup can also help the media buying team learn more about the product.
If the D28 campaign consistently finds users with stronger retention and higher long-term revenue, the account has evidence that part of the valuable audience appears later. Strong D7 performance tells another useful story: early monetizers still contribute enough value to justify their own campaign.
The comparison works best when both sides have enough volume. With a large account, D7 and D28 can become separate acquisition tools with different jobs. With a smaller budget, concentrating signal in one setup may give the team a clearer result.
The choice therefore depends on both the product and the amount of traffic available for the test.
Agency Work Needs More Product Context
Longer optimization windows bring media buying closer to product analytics.
The source dashboard shows delivery and campaign performance, while the client often has a much deeper view of how revenue develops after install. That product context becomes essential when the difference between D7 and D28 depends on what users do several weeks later.
Before choosing the window, ROCKAPP buyers look at the cohort structure and the timing of monetization. They also need to understand how much usable event data each cohort can provide and whether the budget supports the longer evaluation cycle.
That conversation can change the campaign plan before launch. A product may initially look like a natural D28 candidate because its payback period is long, while the actual purchase volume suggests that D7 will give the source a stronger signal. Another product may show enough late revenue to justify a separate D28 campaign alongside the existing D7 setup.
The media buying decision becomes much easier once those product questions have clear answers.
Choosing the Window in Practice
D28 gives Unity Vector access to a longer part of the user lifecycle, but the extra history only becomes useful when the campaign has enough reliable data behind it.
For ROCKAPP buyers, the process starts with understanding when the product creates value. From there, the team can estimate how much signal each cohort will generate and how long the campaign can run before the result becomes mature enough to judge.
D7 gives faster feedback and works well when early monetization already reflects long-term value. D28 becomes more relevant when a meaningful share of revenue develops later and the product has enough data to support a longer optimization window. Running both can make sense for larger accounts where each campaign receives enough volume.
The source can now work with a much longer user history. The media buying team’s job is to decide which part of that history is actually useful for the product and the campaign.
