Attribution Models Explained: Last Click, Multi-Touch & More [2026]

Key Takeaways

• An attribution model is the rule that decides which ad touchpoint gets credit when a user interacts with multiple ads before installing.
• Last Click is the industry default: 100% credit to the final click before install. It's simple, widely supported, and what most ad networks expect.
• Multi-touch models (linear, time decay, data-driven) distribute credit across the full user journey — useful for understanding upper-funnel channel contribution.
• The model you choose changes how budget appears to perform — not necessarily how it actually performs.
• SolarEngine's attribution module supports both Last Click and First Click models with 30+ dimensions for analysis; running secondary models in parallel reveals the full channel picture.

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Table of Contents

1. What Is an Attribution Model?
2. Last Click Attribution
3. First Click Attribution
4. Linear Attribution
5. Time Decay Attribution
6. Data-Driven Attribution
7. Which Model Should You Use?
8. Attribution Windows: The Other Half of the Equation
9. FAQ

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What Is an Attribution Model? {#what-is}

An attribution model is the rule applied by your MMP to decide which ad interaction — out of all the touchpoints a user encountered before installing — receives credit for the conversion.

Most users don't install an app after seeing a single ad. They might see a video ad on Mintegral, then a display ad on Google, then click a retargeting ad on Meta three days later. Who gets credit for the install?

The attribution model answers that question. Different models produce different answers — and therefore different performance numbers for each channel.

The model you use affects how you allocate budget. A channel that looks weak under Last Click might look strong under Time Decay. Understanding what each model measures — and what it hides — is essential before making budget decisions based on attribution data.

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Last Click Attribution {#last-click}

Definition: 100% of conversion credit is assigned to the final ad click before the install occurred.

How it works: The MMP identifies the most recent click interaction within the attribution window and assigns the install to that touchpoint. All prior interactions receive zero credit.

Pros	Cons
Simple and consistent	Ignores all upper-funnel touchpoints
Universally supported by ad networks	Over-credits bottom-funnel channels
Easy to explain to stakeholders	Misleads channel mix analysis
What ad network algorithms expect	Undervalues awareness and discovery channels

When to use it: Last Click is the right default for most mobile app campaigns. It is the model most ad networks use for their own reporting, the model MMP postbacks are built around, and the model campaign optimizations are calibrated to. Use Last Click as your primary model.

When it misleads: If you run significant spend on upper-funnel channels (video, display, influencer), Last Click will attribute nearly all conversions to lower-funnel retargeting ads — making the upper-funnel appear worthless when it was actually driving discovery.

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First Click Attribution {#first-click}

Definition: 100% of conversion credit is assigned to the first ad interaction in the user's journey — the touchpoint that introduced the user to the app.

How it works: The MMP identifies the earliest recorded interaction within the lookback window and assigns full credit to that touchpoint.

Pros	Cons
Measures discovery and awareness	Ignores the conversion touchpoint entirely
Useful for new user acquisition analysis	Not aligned with how ad networks optimize
Highlights which channels introduce new users	Rare as a primary model in mobile UA

When to use it: First Click is most useful as a secondary model run in parallel with Last Click. It reveals which channels are responsible for introducing users to your app — valuable for brand awareness budget decisions and identifying top-of-funnel partners.

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Linear Attribution {#linear}

Definition: Equal credit distributed across all ad touchpoints in the user journey, regardless of position or recency.

Example: A user interacted with 4 ads before installing. Each ad receives 25% of the conversion credit.

Pros	Cons
Acknowledges every touchpoint	Treats all touchpoints as equally valuable
Better full-funnel visibility	Requires multi-touch data collection
Useful for long consideration cycles	Harder to act on for budget optimization

When to use it: Linear attribution is useful for understanding the full channel mix when users have longer consideration periods before installing. It's rarely used as a primary model for mobile UA — it's most valuable as a diagnostic tool to audit whether your entire channel portfolio is contributing.

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Time Decay Attribution {#time-decay}

Definition: More credit is assigned to touchpoints closer to the conversion, with credit decreasing exponentially as you go further back in time.

Example: In a 4-touchpoint journey, the final click might receive 40% credit, the third touchpoint 30%, the second 20%, and the first 10%.

Pros	Cons
Balances recency with full-journey visibility	Requires tuning the decay rate
Better than Last Click for multi-network campaigns	More complex to explain to stakeholders
Acknowledges full-funnel contribution	Limited support in standard MMP reporting

When to use it: Time Decay works well for mobile app campaigns with short consideration cycles (casual games, utility apps) where the final touchpoint genuinely is the most influential — but earlier touchpoints still played a role. It's a practical middle ground between Last Click and full Linear.

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Data-Driven Attribution {#data-driven}

Definition: Credit is distributed algorithmically based on each touchpoint's actual statistical contribution to the conversion outcome, derived from historical campaign data.

How it works: The algorithm compares conversion paths that include a specific touchpoint against paths that don't — and assigns credit proportional to the observed lift in conversion probability.

Pros	Cons
Most accurate multi-touch model	Requires large data volumes to be meaningful
Self-adjusts as campaign patterns change	Black-box — hard to audit or explain
Removes bias from model assumptions	Not available in all MMPs

When to use it: Data-Driven attribution is appropriate for high-volume campaigns (tens of thousands of installs per month) where the statistical sample is large enough for the algorithm to produce reliable results. For smaller campaigns, the model will be unstable and less accurate than simpler alternatives.

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Which Model Should You Use? {#which-model}

The practical answer for most mobile UA teams in 2026:

Scenario	Recommended Model
Primary reporting and optimization	Last Click
Auditing upper-funnel channel value	First Click (secondary)
Long consideration cycle (7+ days)	Time Decay (secondary)
High-volume campaigns (50k+ installs/month)	Data-Driven (if available)
Understanding full channel mix	Linear (diagnostic only)

The most effective approach is to run Last Click as your primary model (for consistency with ad network reporting and postback calibration) while running at least one secondary model in parallel to reveal the contribution of channels that Last Click under-credits.

For a deeper look at how attribution models connect to MMP selection, see Mobile App Attribution: Complete Guide [2026]

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Attribution Windows: The Other Half of the Equation {#windows}

An attribution model determines how credit is distributed. An attribution window determines how long after an ad interaction an install can still be attributed to it.

Window Type	Standard Setting	Notes
Click window	7 days	Most common for mobile apps; extending to 30 days inflates attributed installs
Impression window	24 hours	Shorter because impression intent is weaker than click intent
Re-engagement window	7–30 days	For retargeting campaigns targeting lapsed users

Why window length matters: A 30-day click window attributes installs that happened weeks after the last ad interaction — users who likely would have installed organically anyway. This inflates attributed installs and makes paid channels look more efficient than they are. A 7-day window is the right default for most app categories.

SolarEngine allows clients to configure custom attribution windows per channel, giving UA teams precise control over how credit is assigned across different network types and campaign goals.

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FAQ

Q: What is an attribution model in mobile marketing?
An attribution model is the rule that determines which ad touchpoint receives credit when a user interacts with multiple ads before installing an app. Different models — Last Click, First Click, Linear, Time Decay, Data-Driven — distribute credit differently, producing different performance numbers for each channel.

Q: What is Last Click attribution?
Last Click attribution assigns 100% of conversion credit to the final ad click before an install. It is the industry standard for mobile app campaigns because it is simple, consistent, and aligned with how ad network algorithms are calibrated. Most MMPs default to Last Click as the primary attribution model.

Q: What is multi-touch attribution?
Multi-touch attribution distributes credit across multiple ad touchpoints in a user's journey before conversion. Models include Linear (equal distribution), Time Decay (more credit to recent touchpoints), and Data-Driven (algorithmic distribution based on statistical contribution). Multi-touch models provide a more complete picture of channel contribution but are more complex to implement and act on.

Q: Should I use Last Click or multi-touch attribution?
Use Last Click as your primary model for reporting and optimization — it's what ad networks expect and what postbacks are calibrated to. Run a secondary multi-touch model (First Click or Time Decay) in parallel to audit channel contribution across the full funnel. Don't make budget cuts based on Last Click alone if you run significant upper-funnel spend.

Q: What is an attribution window?
An attribution window is the time period after an ad interaction during which an install can still be credited to that ad. A 7-day click window is the standard for most mobile apps. Installs that occur after the window closes are credited as organic regardless of prior ad interactions.

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Conclusion

Attribution models are not just a technical setting — they are a lens that shapes how your team sees performance. Last Click is the right primary model for most mobile UA teams. But running secondary models reveals the full story of how your channels work together to drive installs.

The best attribution setup uses the right model for the right purpose: Last Click for optimization, multi-touch for channel auditing, and custom windows calibrated to your app's actual consideration cycle.

Configure your attribution model with SolarEngine → — set up Last Click, First Click, custom windows, and postback rules across all your channels from a single platform.