Thursday, May 28, 2026


Measuring the true impact of your marketing spend is complex, especially when you look across channels and mediums. In Episode 6 of Google's Ads DevCast, "The 'What' and 'Why' on Meridian," we sit down with Product Manager Katie Munro and Developer Relations Engineer Jeff Li to explore Meridian, Google's open-source Marketing Mix Modeling (MMM) framework, and how it helps advertisers make data-backed strategic budget decisions.


[Watch the full episode](http://goo.gle/watchadsdevcast)


[Hear the full episode](http://goo.gle/listenadsdevcast)


Here is a summary of the talking points from our discussion on what Meridian is, how the math works, and the newly announced surfaces to help you implement it.

### What is Meridian?

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Meridian is Google's open-source Marketing Mix Modeling (MMM) framework. It provides a holistic, privacy-safe view of marketing ROI by analyzing aggregated historical data across all channels (digital, TV, print) alongside non-advertising factors (seasonality, economic conditions). It helps you determine the incremental lift of your marketing (sales caused by ads) versus baseline sales (sales that would have happened anyway).

### The Core Math: Hill Curves \& Adstock

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Meridian uses statistical models to capture the real-world behavior of advertising:

- **Hill Curves:** Models diminishing returns, showing where you have room to increase spend (headroom) and where you have saturated a channel.
- **Adstock:** Models the lagged effect and decay of advertising over time, capturing the delay between seeing an ad and making a purchase.

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### The Measurement Trifecta

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Meridian completes the modern measurement framework:

- **Attribution (GA4):** For day-to-day tactical campaign tweaks.
- **Incrementality Experiments (Meridian GeoX):** To test specific hypotheses in the real world.
- **MMM (Meridian):** For macro-level, strategic budget planning.

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### New Meridian Releases from GML 2026

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We discuss three major additions designed to make MMM more accessible and accurate:

- **Meridian in GA360:** A turnkey, integrated MMM solution within Google Analytics 360 that uses existing behavioral data to provide cross-channel ROI insights without requiring a data science background.
- **Meridian Studio:** A Google Cloud-based enterprise platform to build and scale models, featuring native agentic AI to automate data quality checks, suggest model health improvements, and assist in scenario planning.
- **Meridian GeoX:** An open-source geo-based incrementality solution that acts as a calibration engine, allowing you to run geographic experiments and feed "ground truth" causation data back into your Meridian model.

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### Next Steps:

- Watch the full episode on [YouTube](https://goo.gle/watchadsdevcast) (or [listen](https://goo.gle/listenadsdevcast) to it)
- Try Meridian: <https://goo.gle/try-meridian>
- Try Meridian Studio: <https://goo.gle/try-meridian-studio>
- Try Meridian GeoX: <https://goo.gle/try-meridian-geox>
- Check out the [Meridian Developers website](https://developers.google.com/meridian) to read the documentation.
- Join our developer community on [Discord](https://discord.gg/googlemeridian) to ask questions and discuss.

|---|---|
| ![Portrait of the author](https://developers.google.com/static/ads/blog/images/AN66SAzPW9gtIDxKGgbRWCyVWTJjciMUxMUJDdSI-lmdBw=s60-p-rw-no-il.jpg) | [Cory Liseno](https://linkedin.com/in/coryliseno) Google's Advertising and Measurement Developer Relations team |

**Labels:**

[measurement](https://developers.google.com/ads/blog/feeds/labels/measurement.md.txt),

[meridian](https://developers.google.com/ads/blog/feeds/labels/meridian.md.txt),

[mmm](https://developers.google.com/ads/blog/feeds/labels/mmm.md.txt),

[open-source](https://developers.google.com/ads/blog/feeds/labels/open-source.md.txt),

[podcast](https://developers.google.com/ads/blog/feeds/labels/podcast.md.txt)