Google Ads mistakes we still see in the AI Max era

Google Ads spends your money well when you feed it good information, and very quickly when you don't. Most advertisers still bring the old instinct to it: control. Single keyword ad groups. Granular everything. Every query steered by hand.

That instinct now works against you. AdWords is now Google Ads, the platform runs on machine learning, and Google's own guidance says you don't need to split keywords by match type when you use broad match with Smart Bidding. Performance Max decides where your ads show across Google's inventory. AI Max for Search can match your ads to searches you never added as keywords and write headlines on the fly.

The mistakes have changed with it. Here are the ones we find most often when we open a small business account.

Mistake 1: Feeding the machine bad conversions

It's the most expensive mistake in any automated account, because automated bidding learns from whatever you tell it is a conversion.

If your conversion action is "visited the contact page," Google will find you lots of people who visit the contact page. If it counts every form fill, including spam and job seekers, Google will happily find you more spam and job seekers. Smart Bidding is only as smart as the conversions you feed it.

Fix it this week. Make your primary conversions the actions that make money: purchases, booked appointments, qualified calls over a set length. Turn on enhanced conversions. If you sell offline, send your qualified and closed leads back into Google Ads so bidding can learn which clicks became customers. And if you have customers in the EEA, make sure your consent setup passes the signals Google now expects.

Mistake 2: Fighting broad match with a 2015 playbook

We'll own this one. Single keyword ad groups made sense when you bid manually and match types meant what they said. Today they starve automated bidding of data, splitting a small budget into dozens of ad groups that never collect enough conversions to learn.

Google recommends broad match only with Smart Bidding (Maximize conversions, Maximize conversion value, Target CPA or Target ROAS), and strongly advises against pairing it with manual bids. That is the right instinct. Broad match with manual CPCs is a fast way to buy a lot of irrelevant clicks.

What works now: fewer campaigns, tightly themed ad groups, broad match where conversion tracking is solid, and phrase or exact match where you need to hold the line on cost.

Mistake 3: Never reading the search terms

Negative keywords still matter. Read your search terms report, find the queries that don't fit, and exclude them. A hot dog stand should block "veggie hot dogs." The idea hasn't changed. There are just more places to look now.

Performance Max used to be a black box here. That changed in 2025, when Google rolled out campaign-level negative keywords for Performance Max to all advertisers and added a source column to search term insights. AI Max adds its own match type to the search terms report, plus a column showing whether a query came from broad match expansion or keywordless matching.

So there is no excuse left. Block irrelevant queries weekly while a campaign is new, then monthly once it settles.

Mistake 4: Letting automation pick your landing pages and your brand terms

AI Max includes final URL expansion, which can send traffic to whichever page on your site Google thinks will convert best. Sometimes it picks well. Sometimes it sends paid clicks to your blog, your careers page or a product you discontinued.

Use the controls. AI Max lets you exclude specific URLs from serving as landing pages, and set brand inclusions or exclusions. Keep your own brand searches in a separate campaign so a cheap branded conversion doesn't make an automated campaign look better than it is. The same thinking applies to Performance Max: if it is claiming most of its conversions from people who already searched your name, it is taking credit, not creating demand.

Mistake 5: Setting it and forgetting it while Google moves the furniture

Google is changing the defaults under you. It announced that automatically created assets and the campaign-level broad match setting would move into AI Max starting in September 2026. Automatic upgrades from Dynamic Search Ads to AI Max are now scheduled for February 2027, after Google pushed the date back from September. Ads from Search, Shopping and Performance Max campaigns can also show inside AI Overviews.

None of that is bad news by itself. It does mean an account that was set up two years ago and left alone is not running the way you think it is.

What to do before your next budget increase

Open your account and answer four questions. What counts as a conversion, and is it real money? Which searches triggered your ads last month? Which pages are getting paid clicks? How much of your reported performance is people who already knew your name?

If you can't answer all four in an afternoon, don't raise the budget yet. Fix the inputs first. That is where most of the waste lives, and it is the first thing our paid search team looks at when a new client hands us the keys.