Intent to Extend Origin Trial: Conversion Measurement API

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John Delaney

Jan 14, 2021, 2:17:26 PM1/14/21
to blink-dev

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Design docs/spec:


This is a new API for measuring conversions (e.g. purchases) and attributing them to clicked ads, without using cross-site persistent identifiers like third party cookies.

Link to “Intent to Prototype” blink-dev discussion

Link to “Intent to Experiment” blink-dev discussion

Goals for experimentation

For a continuation of the trial, we still hope to see that the measurement data made available through the API produces comparable results to existing click through measurement solutions on the web.

Experimental timeline

We'd like to extend the origin trial for three additional milestones, continuing through M91.

Any risks when the experiment finishes?

This API is only additive and does not affect any existing state. Current conversion measurement solutions will work as expected with and without the API, so we don’t believe there are any risks.

Some breaking changes are being made in Chrome 89 regarding attribute parsing and format, which will force developers to update their solutions and help avoid burn in.


Reason this experiment is being extended

The original origin Trial was slated for Chrome 86 through Chrome 88, but we did not have partner experiments start until the M87 timeframe, therefore we are only looking at 2 milestones of data and feedback. 

This was partially impacted by the holiday season, which made launching new experiments difficult.

We received feedback from partners citing pain points regarding an issue where the Origin Trial feature was gated behind a separate field trialed feature. This has been resolved in the M88 release. Extending the trial will allow partners to experiment further without this issue.

In M89 we added support for a new interface which is necessary for some parties to experiment with the API. Extending the Original Trial will allow these parties to also evaluate the effectiveness of the API.


Ongoing technical constraints


Will this feature be supported on all five Blink platforms supported by Origin Trials (Windows, Mac, Linux, Chrome OS, and Android)?


Link to entry on the feature dashboard

Mike West

Jan 14, 2021, 2:48:13 PM1/14/21
to John Delaney, blink-dev
It sounds like the field trial dependency complicated deployment and hampered partners' ability to experiment with y'all, but that you're now getting ongoing feedback from partners. Moreover, you're learning from that feedback and adjusting the API accordingly in ways that mitigate the risk of accidental burn-in.

LGTM to extend the origin trial through M91.

Two followup questions, though:

1.  Do you also plan to shift this to a third-party origin trial, as you suggested in the original intent?
2.  Can you share any summary of the initial feedback you've been able to gather from partners?


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