Microsoft Ads Tied PMax Conversions to Each Publisher URL Google Still Hides

Microsoft Advertising added conversion and spend metrics to its Performance Max Website Publisher URL report in late April 2026, exposing spend tied to specific publisher domains for the first time. Google Performance Max only added Search Partner placement visibility in February 2026, and its channel-level data remains read-only. The practical edge: Microsoft advertisers can now build URL exclusion lists from real conversion math, not impressions.

What changed in the report

Until this update, Microsoft's PMax Website Publisher URL view gave you placement names, impressions, and clicks, according to Search Engine Land. Useful for noticing where your money was going, useless for deciding what to do about it. You could see that a domain ran 200,000 impressions on your campaign, but you couldn't see whether it converted twice or fifty times.

The new fields close that loop. Microsoft's April product update confirms the report now includes spend, conversions, conversion value, and ROAS by publisher URL, plus segmenting by campaign, asset group, and final URL. Microsoft also flagged "auction insights and additional metrics in the publisher URL report" as part of the roadmap, which is the polite way of saying the current view is still partial.

Navah Hopkins, Microsoft Ads' product liaison, framed the launch as "moving beyond basic placement visibility into actionable performance data." Translation: the previous report was decoration.

Google's read-only catch

Google added Search Partner placement names to PMax's "When and where ads showed" report in February 2026, per AdExchanger, and added audience exclusions, budget reporting, and demographic breakdowns in April. Sounds like parity. It isn't.

The channel-level performance data inside Google PMax stays read-only. You can see that an asset group spent X on Display and Y on Search Partners. You cannot pull conversions tied to a specific publisher URL the way you now can in Microsoft. You also cannot bid differently per surface or block spend from flowing to a low-converting placement at the URL level inside the campaign itself. Account-level placement exclusions became available in January 2026 and are the workaround, but they cap at 65,000 entries per account, and the data you'd use to build that list is, well, the data Google still does not surface.

So the asymmetry as of May 2026 looks like this. Microsoft tells you which publisher URL converted at what cost. Google tells you a placement existed, you can exclude it, and it will not break out spend or conversions for that URL inside PMax. One platform gives you the math. The other gives you the door.

The honesty test on a "transparency update" is whether the new data makes a different decision possible. Microsoft's does. Google's mostly lets you confirm what you suspected.

Why this matters more for the smaller platform

Microsoft Ads has spent years trailing Google in the PPC migration story. The pitch has always been "easier to manage if you copy your Google account over." That pitch ages badly when the smaller platform mirrors the bigger platform's opacity. Adding publisher-level conversion math is the clearest distinct selling point Microsoft has shipped in PMax since launch. It also lines up with Bing's pattern this year of disclosing things Google still hides, including AI citation share data ahead of Google.

The competitive read for Microsoft is not "we caught up." It's "we expose what they refuse to." That's a real argument for the budget-allocation conversation a CMO has on Tuesday.

I think most teams running PMax across both platforms will quietly start using the Microsoft data to inform their Google account-level exclusions. The publisher URLs that bleed money on Microsoft are not always the same on Google, but the overlap on junk MFA domains and broken app inventory is high enough to use as a starting list. Lunio's analysis last year found roughly 41% of placements in PMax are junk, with content farms, made-for-advertising sites, and accidental-click mobile games dominating the bottom of the distribution. Microsoft's report can finally tell you which of those wasted real spend in your account.

How to actually use this on Monday

Pull the Website Publisher URL report from your Microsoft Ads account, segmented by campaign and date range covering at least the last 30 days. Sort by spend descending. Anything with spend above 1% of the campaign total and zero conversions is your starting exclusion list.

Then take that URL list, paste it into your Google Ads account-level placement exclusions (Tools and Settings, then Shared Library, then Exclusion Lists, then add placements, then Enter multiple placements). You can paste up to 20,000 at a time, with a hard cap of 65,000 per account. This is the move that actually saves money. The Microsoft data is the diagnostic. The Google exclusion is the action.

If you only run on Google, you still benefit indirectly. Several practitioner exclusion lists on Reddit's r/PPC compile junk URLs across both platforms. The Microsoft transparency makes those community lists more accurate over time.

A reasonable benchmark from accounts I've seen discussed publicly: a tightly applied exclusion list typically recovers 8 to 15% of PMax spend and reroutes it to surfaces that actually convert. That gain doesn't show up in headline ROAS numbers, but it shows up in cost per acquisition over a 30-day window.

One operational note. PMax exclusions only work on placements you can name. You will not get back spend lost to broad asset-group bleed into Display partners that Microsoft doesn't yet list out. The new report covers the publisher URL surface, not every surface PMax serves on. Treat the 8 to 15% recovery range as the ceiling for what URL exclusions alone can do. The rest of the leakage gets recovered through asset group restructuring, conversion goal re-weighting, and final URL cleanup, which the new Final URL report at least makes inspectable.

The data quality bottleneck the report finally fixes

The bottleneck on PMax exclusion lists has always been data quality, not tooling. You can paste 65,000 URLs into Google. You just need to know which 65,000. Until now, the answer was "buy a list, scrape r/PPC, or guess." Microsoft's new report gives accounts running on both platforms a clean source: spend with no conversion attached, broken out by URL, segmented by asset group.

The work is unglamorous. Pull the report monthly, dedupe against your existing exclusion list, push the new entries up. Set a calendar reminder. There is no automation for this yet.

Microsoft's roadmap mentions auction insights and additional publisher URL metrics. If those ship cleanly, the report becomes the canonical placement audit for advertisers running both platforms. If they don't, this is still the most useful PMax reporting update either platform has shipped this year.

Where to keep an eye on this

The story to watch is whether Google responds. Google has historically added transparency only when forced by regulator pressure or competitive embarrassment. Microsoft just gave them the second one. From what I've seen, Google's PMax product team tends to ship parity features within two quarters of a Microsoft transparency move, but they tend to ship them with worse segmentation. So expect a Google announcement at some point this summer. Expect it to fall short of what Microsoft just released.

The bigger pattern, and the part I'd actually plan around, is that the smaller search platforms are now competing on disclosure rather than features. That's a change worth pricing into how you split test budgets across them this year. Don't move all your money on a reporting update. But don't keep treating Microsoft as a clone account either.

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