Stop Guessing: How to Know If Your Google Ads Are Actually Working

The Short Version

Google Ads is working when it generates profitable sales, not just traffic. The metrics to watch are ROAS, CPA, conversion rate, CTR, and impression share. But none of those numbers mean much without context. A solid-looking ROAS can still be losing you money if your tracking is broken, your margins are thin, or the rest of your marketing system isn’t pulling its weight.

Most Shopify Stores Are Flying Blind

Here’s what usually happens. You log into Google Ads, see impressions ticking up, clicks coming through, maybe even some conversions showing. Looks fine on the surface.

But are you actually making money?

That’s a different question. And most store owners can’t honestly answer it, because they’re looking at the wrong numbers, in the wrong place, at the wrong level of detail.

Google Ads without a clear measurement framework is expensive guesswork. You’re paying for signals you can’t read.

The Metrics That Actually Tell You Something

There are five numbers worth tracking. Not because they’re the only ones, but because each one reveals a different part of what’s working and what isn’t.

ROAS: Is Your Ad Spend Generating a Return?

ROAS stands for Return on Ad Spend. It’s calculated as revenue divided by ad spend. A ROAS of 4 means for every dollar you put in, four came back.

But here’s the problem most stores run into: they track ROAS at the account level and stop there.

A 4x account average can hide a campaign running at 10x and another burning budget at 0.8x. The average looks fine. The budget allocation is a mess.

ROAS also tells you nothing about profit. If your margins are tight, a 3x ROAS might still be losing you money once you account for shipping, returns, and cost of goods. Your break-even ROAS matters more than any generic benchmark.

CPA: What Does It Cost to Get a Customer?

CPA, or cost per acquisition, is what you’re paying on average to turn a click into a customer.

The benchmark that matters here is your own. If your average order value is $80 and your CPA is $95, you’re acquiring customers at a loss. If your CPA suddenly spikes without a corresponding drop in revenue, something has changed and it needs investigating.

Common culprits include creeping bid costs, a landing page issue killing conversion rate, or a seasonal shift in buyer intent. None of these fix themselves.

Conversion Rate: Are Clicks Turning Into Sales?

Your conversion rate tells you what percentage of people who click your ads actually buy something.

Most Shopify stores running paid search should be aiming for somewhere between 2% and 4%. If you’re sitting under 1%, the problem is rarely the ads themselves. It’s usually the page they land on.

Slow load times, confusing navigation, a price that doesn’t match the promise in the ad, a mobile experience that’s been neglected. These are the things that kill conversion rate. And if you’re pouring budget into campaigns without fixing the underlying page issues, you’re paying to highlight a broken funnel.

This is one of the most common reasons Google Ads underperforms. The ad does its job. The rest of the system doesn’t. We go into this in detail in Fixing Google Ads That Don’t Convert.

CTR: Are Your Ads Getting Attention?

Click-through rate measures how often someone sees your ad and decides to click it.

A low CTR usually means one of two things: your ads aren’t relevant to the search, or they’re not compelling enough to act on. Both are fixable, but they need different approaches.

Rough benchmarks for search campaigns sit around 3% to 6%. For display, 1% to 2% is more typical. Below those, it’s worth checking whether your headlines match the intent of the keywords you’re bidding on, and whether you’re leading with a benefit or just a description of what you sell.

Impression Share: Are You Missing Opportunities?

Impression share shows you what percentage of eligible searches your ads actually appeared for.

Lost impression share comes from two places: budget (you ran out of money before the day ended) or rank (your Quality Score isn’t competitive enough). Both are worth addressing, but they need different fixes. Throwing more budget at a low-Quality-Score campaign is one of the fastest ways to burn through cash without improving results.

We cover this in more detail in Why Google Ads Burn Through Cash.

Why the Numbers Can Lie

Here’s the part most guides skip over.

All of these metrics depend on your tracking being set up correctly. If your conversion tracking is miscounting, double-counting, or not firing at all, every number in your account is unreliable. You could be optimising toward data that doesn’t reflect what’s actually happening in your store.

Broken tracking is more common than most people realise. It usually happens after a website migration, a theme update, an app conflict, or when someone installs a tag and forgets to test it.

Before you draw conclusions from your Google Ads data, it’s worth verifying that the foundation is solid. If the numbers look odd, tracking is usually the first place to check.

What Most Shopify Stores Get Wrong

Looking at five metrics in isolation doesn’t tell you whether your Google Ads are working. It tells you what the symptoms are.

The real question is: where in your system is the breakdown?

• If ROAS is low, is it the campaign structure, the product margin, the landing page, or the offer?
• If CPA is high, is it the bid strategy, the audience, the creative, or the follow-up after the click?
• If conversion rate is low, is it the page, the price, the trust signals, or the traffic quality?

Most businesses know something’s not working. Pinpointing which part of the system is the problem, and fixing it in the right order, is where the real skill lies. What Shopify Founders Get Wrong About Google Ads

If you’re running Google Ads and not seeing results you can stand behind, our Google Ads management service covers campaign structure, tracking, landing pages, and ongoing optimisation, built around your margins and growth targets.

You might also find this useful: What Shopify Founders Get Wrong About Google Ads.

Frequently Asked Questions

What is the difference between ROAS and ROI for Google Ads?

ROAS measures revenue returned for every dollar spent on ads. ROI is broader and includes all business costs, such as cost of goods, staff, fulfilment, and overheads. A campaign can show a strong ROAS and still be unprofitable if the broader margins don’t hold up.

What is a good ROAS for Shopify Google Ads?

There’s no universal answer. Your break-even ROAS depends on your profit margin. A product with a 60% margin has much more room than one at 20%. As a starting point, 3x to 5x is a common target for healthy Shopify stores, but this only makes sense once you know your own numbers.

Why does my conversion rate matter for Google Ads?

Google Ads brings people to your site. Your conversion rate determines how many of those people actually buy. If your landing page isn’t set up to convert, more ad spend makes the problem more expensive, not better.

How often should I review my Google Ads metrics?

Weekly for any campaign with significant spend. Monthly for overall strategy review. The goal is to catch changes early. A sudden CPA spike or drop in conversion rate usually means something specific has shifted and needs attention.

Do I need Google Tag Manager for Google Ads tracking?

Not strictly, but it makes accurate tracking significantly easier to manage and test. Direct installation through Shopify works for basic setups. GTM gives you more control over what fires, when, and how, which matters when you’re troubleshooting or making changes.

Not Sure Where Your Ads Are Losing Money?

If you’ve read through this and you’re still not sure whether your Google Ads are actually working, that’s the real signal.

A Business Scalability Audit looks at your full marketing system, including traffic, tracking, conversion, and spend, and shows you exactly where the gaps are and what to fix first. Book a Business Scalability Audit