Performance Max Not Working? Brand Cannibalisation, Junk Leads and the Fixes That Work

Two messages landed in our inbox on the same Monday. A Toronto real estate brokerage said its Performance Max campaign was producing leads at CAD 71 each, "the best CPL we've ever had", while its sales team said most numbers didn't pick up. A US home services company said PMax showed a 9x ROAS, yet total sales hadn't moved since launch and its brand Search campaign had gone quiet.

Neither campaign was broken in the technical sense. Both were doing exactly what PMax is built to do: find the conversions its goals reward, wherever they are cheapest. If your Performance Max is not working, the fix is rarely a new campaign. It's telling Google more precisely what a good result looks like and closing the doors it has been walking through.

What's changed in Performance Max since 2025?

If your view of PMax was formed in 2022 or 2023, it's out of date. Google spent 2025 adding the controls advertisers had been asking for, and PPC Land's round-up lists most of them.

• Campaign-level negative keywords. Announced in January 2025. The limit rose from 100 to 10,000 per campaign in March 2025, and Google's April 2025 update confirmed it was live in all PMax campaigns. Negative keyword lists followed later in the year.
• Full search terms report. Announced on 30 April 2025 with the same granularity as Search campaigns, on top of the older Search terms insights.
• Channel performance report. Shows clicks, conversions, value and cost across Search, YouTube, Display, Discover, Gmail, Maps and Search partners. It reached all PMax campaigns in November 2025.
• Demographic exclusions and device targeting moved to general availability, along with asset group performance downloads and Final URL expansion reporting.
• Customer acquisition reporting. Google added a customer acquisition cost column for the new customer acquisition goal in April 2025, and the high value mode left beta later that year. E-commerce brands worried about PMax chasing repeat buyers now have a way to bid more for genuinely new ones.

Brand exclusions are older, dating to Google's June 2023 announcement, which says they also block misspellings and brand searches in other languages. Google's current help page says they apply to Search, Shopping and YouTube search inventory in PMax.

2026 has brought more. At Google Marketing Live on 20 May 2026, Google announced a batch of lead generation tools, including lead intent scores, AI-qualified call conversions and bidding that learns from the full lead-to-sale path, as PPC Land summarised. Most had no general availability date at the time. In July 2026, Google confirmed to Digiday that a small alpha group could switch off Search partners and the Display Network inside PMax. If you don't see those checkboxes, you're not in the alpha.

Is Performance Max cannibalising your Search campaigns?

Probably, to some degree. Google says an exact match Search keyword identical to the query should take priority over PMax, but in practice overlap is everywhere. Optmyzr studied more than 500 accounts in February 2025 and found PMax serving on search terms that exactly matched a Search keyword in most of them.

Overlap alone isn't a crime. What matters is who performs better when both campaigns compete for the same query. In most cases there was no meaningful difference. When there was one, Search usually won.

Optmyzr couldn't compare cost per conversion because Google didn't report PMax search term cost at the time. It also warns that PMax can still catch fuzzy brand variants even with brand exclusions on, and suggests adding branded misspellings as exact match keywords in your brand campaign.

To size your own brand leak, pull the last 30 days of PMax search terms, filter for your brand and its misspellings, and add up the conversions. Then compare total brand conversions across all campaigns for the month before PMax launched and the month after. If the total barely moved while PMax claims a big slice of it, PMax has mostly relabelled sales you already had. For a cleaner answer, apply brand exclusions for four weeks with the brand Search campaign running, and compare total account conversions, not PMax's share, against the four weeks before.

How to diagnose a Performance Max campaign that isn't working

Run these checks before touching bids or budgets. Most take a couple of minutes each in the Google Ads interface.

Google notes the placement report is a brand safety tool showing impressions, not a performance report. Use it to spot junk, not to judge results.

Why Performance Max stops working: root causes ranked

Ranked by how often we find each one in the PMax accounts we audit, most common first.

1. PMax is harvesting your brand searches

Brand clicks are cheap and convert well, so they flatter PMax's numbers. If your brand Search campaign lost impressions when PMax launched while total conversions stayed flat, you're paying for demand you already had.

2. The conversion goal rewards junk leads

For lead generation this is the big one. If "Submit lead form" is the primary goal, PMax will find the cheapest form fills it can, and Display and app inventory produce plenty of them. Accidental taps, bots and people who wanted a job, not a quote, all count the same.

3. Wrong actions counted as conversions

We still see accounts where a thank-you page view fires twice, or where every call over a few seconds counts as a lead. The setup issues behind this are covered in our guide to fixing Google Ads conversion tracking.

4. Final URL expansion sends people to the wrong pages

With expansion on, PMax can choose landing pages from your whole site. Great for a large catalogue. Less great when it sends "condos for sale Liberty Village" traffic to a 2019 blog post.

5. Too little data, too many asset groups

Optmyzr's 2025 analysis cites around 60 or more conversions a month as a working benchmark for PMax. Splitting 40 monthly conversions across six asset groups leaves the system guessing.

6. Feed and asset gaps

Disapproved products, missing videos or thin assets limit where ads can serve. The Channel performance report flags these as "Missing required assets" or "Eligible (Limited)".

7. Audience signals and search themes treated as targeting

Audience signals and search themes are hints that help PMax start, not fences. An asset group "targeted" at a CRM list of high-value buyers will still reach far beyond that list once the system finds cheaper conversions elsewhere. We regularly meet advertisers who believe their PMax only reaches past customers or only one city's searches. It doesn't. Location settings, exclusions and negatives are the real controls; signals simply shape where learning begins.

How to fix Performance Max: a step-by-step plan

1. Separate brand from prospectingRun a brand Search campaign with exact and phrase match brand terms, including common misspellings. In PMax, go to Settings › Additional settings › Brand exclusions and apply a brand list with your own brand. Watch total conversions, not just PMax's, for two weeks.
2. Add negatives where they belongPut universal junk terms (jobs, salary, free, course, login, complaint) in account-level negative keywords under Admin › Account settings, which apply across Search and Shopping inventory. Use PMax campaign negatives or shared negative keyword lists for campaign-specific exclusions.
3. Make qualified leads the primary goalIn Goals › Conversions › Summary, set raw form submissions as secondary and a qualified lead or converted lead action as primary. Google's lead gen guidance in its Performance Max FAQ recommends goals close to the final sale, with enough volume to optimise.
4. Close the CRM loopSet up enhanced conversions for leads or offline conversion imports so stage changes in HubSpot, Pipedrive or Salesforce flow back with the GCLID or hashed email. At Google Marketing Live 2026, Google added direct Data Manager integrations for tools such as Klaviyo, Mailchimp and ActiveCampaign.
5. Add value, then bid on itOnce qualified leads flow back, assign values by stage and move to Maximize conversion value or a target ROAS. Conversion value rules can raise values for high-value locations or audiences.
6. Harden your formsAdd reCAPTCHA, server-side validation and a qualifying question. On Google lead form assets, mark a multiple-choice question as a qualifying question so strong leads are tagged in your data.
7. Read the Channel performance reportIf Display or Search partners take spend with no qualified conversions, tighten account-level placement exclusions under Tools › Content suitability. If you're in the alpha, untick Search partners or Display in the campaign.
8. Control landing pagesTurn off Final URL expansion for lead gen campaigns, or keep it on with URL exclusions for blog, careers and policy paths.
9. Consolidate and waitMerge thin asset groups so each one has a clear theme and enough data. After a significant change, Google advises allowing one to two weeks for performance to stabilise.

Mistakes that make Performance Max worse

Most of these come from good intentions and impatience.

• Pausing and relaunching. A fresh campaign starts learning from zero. Fix the inputs of the existing one instead.
• Setting a target CPA from a spreadsheet. A target far below what the campaign currently achieves throttles delivery. Start near actual results and tighten in steps of 10 to 15%.
• Excluding your brand without a brand campaign. You'll lose those conversions entirely, or hand them to competitors bidding on your name.
• Feeding back every lead as a conversion. If the CRM sends "lead created" for every junk submission, you've just confirmed the junk is what you want.
• Over-splitting asset groups by audience signal. Audience signals are hints, not targeting. Ten asset groups with the same landing page rarely beat two good ones.
• Judging PMax on its own ROAS. Check blended account results and new-customer numbers. The same trap exists on Meta, as our post on Advantage+ campaigns explains.

How to keep Performance Max on track

This is the cadence we run on client accounts under our Google Ads management service.

Worked scenario: a Toronto real estate brokerage (illustrative)

These numbers are illustrative, built to show the method. They aren't a client result.

A Toronto brokerage with a team of 14 agents spends CAD 45,000 a month on one lead gen PMax campaign, chasing pre-construction condo buyers across the GTA. "Submit lead form" is its only primary conversion. Google Ads reports 630 leads at about CAD 71 each, but the agents qualify only 7% of them, so each qualified lead really costs around CAD 1,020.

The search terms report shows the brokerage's own name and two misspellings among the top converting terms. The Channel distribution table shows Display and Search partners taking 38% of spend but producing almost no leads that reach a showing. Final URL expansion has been sending traffic to an old French-language page about joining the brokerage as an agent.

The team moves CAD 4,500 a month into a brand Search campaign and applies brand exclusions in PMax. They add 140 account-level negatives (rentals, room for rent, real estate licence course, agent jobs), turn off Final URL expansion and add a budget and timeline question to the form. Follow Up Boss starts sending "Qualified" and "Showing booked" stages back through offline conversion imports, valued at CAD 150 and CAD 600. After three weeks of data, bidding moves to Maximize conversion value.

On the Google Ads dashboard, CPL almost doubled. In the sales pipeline, qualified leads more than doubled for the same budget. That's what fixing PMax usually looks like. The same structure works for a dental group in Manchester or a roofing firm in Texas; our dentist PPC guide shows how lead stages map for clinics.