Here's a scenario I've seen dozens of times. A founder is spending $5,000 to $10,000 a month on Meta and Google Ads. They check ROAS in their ad manager. It says 4x. They feel good. They keep spending.
Then one month, cash gets tight. They cut ad spend by 40%. Revenue barely moves.
That's when the uncomfortable question lands: was that ad spend actually doing anything?
The answer is usually yes, partially. But the real picture is almost always different from what the ad platforms tell you. Here's how to figure out what's actually working.
The ROAS number in your ad manager is lying to you. Here's why.
Meta and Google both have a strong incentive to show you high ROAS. They want you to keep spending. So they both take credit for as many conversions as possible.
Meta uses a 7-day click, 1-day view attribution window by default. That means if someone saw your ad on Monday, didn't click, and then bought on Thursday by Googling your brand name, Meta counts that sale. Google would also count that same sale if the person clicked a branded search ad.
The result: both platforms claim credit for the same purchase. Your combined ROAS looks incredible. But the reality is you're double counting.
Quick gut check: Add up the revenue each ad platform claims it drove. If the total is higher than your actual store revenue, you know the numbers are inflated. I've seen cases where Meta + Google claimed 140% of total revenue. That's not a rounding error. That's a measurement problem.
The 3 numbers that actually tell you if your ads are working
Forget ROAS for a minute. These three metrics give you a much clearer picture of whether your ad spend is generating real, incremental growth.
1. New customer acquisition rate. What percentage of your orders this month came from first-time buyers? If you're spending $5K on ads and 80% of your revenue is from repeat customers who were going to buy anyway, your ads aren't doing what you think. Track this in your eCommerce platform. Most have a "new vs returning customer" report.
2. Blended CAC (customer acquisition cost). Take your total marketing spend for the month. Divide it by the number of new customers acquired. Not the number Meta says it acquired. The actual number of new customers in your store. This single number tells you more than any platform-level ROAS ever will.
3. Organic traffic trend. If your organic and direct traffic is growing while you're running ads, your ads are building awareness that converts through other channels. If organic traffic is flat or declining, your paid spend is doing all the heavy lifting and that's a fragile position to be in.
The "turn it off" test most founders are too scared to run
The most reliable way to know if your ads are working is to turn them off. Not all of them. Pick one campaign or one channel and pause it for two weeks. Watch what happens to your total revenue.
If revenue drops proportionally, the campaign was driving real incremental sales. Keep it running.
If revenue barely changes, the campaign was mostly taking credit for organic demand. Reallocate that budget somewhere else.
I know this feels risky. But running this test once gives you more clarity than months of staring at ROAS dashboards. The founders who actually know their numbers are the ones willing to test their assumptions.
A real pattern I've seen: A DTC brand paused their branded Google search campaigns ($1,200/month). Revenue from Google dropped by $1,200. But total store revenue only dropped by $300. The other $900 in "Google revenue" was just people who would have typed the URL directly. They saved $900/month with zero impact on sales.
Where to shift budget when you find waste
Once you've identified which campaigns are inflating their numbers, you've got budget to redeploy. Here's where it usually has the most impact for brands in the $500K to $5M range.
Top-of-funnel Meta creative. If your prospecting campaigns are genuinely bringing in new customers (check new customer rate), invest more here. Creative fatigue is the biggest killer. Refresh your ads every 3 to 4 weeks.
Email and SMS flows. If you're spending money to acquire customers and not emailing them afterward, you're leaving the easiest revenue on the table. A basic welcome series, abandoned cart flow, and post-purchase sequence can generate 20 to 30% of total revenue with near-zero marginal cost.
Site conversion optimization. Before spending more on traffic, make sure your site converts the traffic you already have. A 0.5% improvement in conversion rate has the same revenue impact as a 20% increase in traffic. And it costs nothing.
The real problem isn't your ads. It's visibility.
Most founders aren't making bad decisions about ad spend. They're making uninformed decisions. The data exists to answer every question in this article. It's sitting in your Shopify admin, your GA4, your Meta Ads manager, and your Google Ads dashboard. The problem is that nobody is connecting those data sources and giving you a clear, honest answer every week.
That's not a tools problem. It's an attention problem. You're running a business. You don't have three hours every Monday to pull reports, cross-reference platforms, and do the math.
That's the job Tracerly does for you.
We connect to your ad accounts, your store, and your analytics. Every week, you get a report that tells you what's actually driving revenue, what's wasting money, and where to focus your budget next.
Get your free performance audit →If you run the three checks in this article, you'll already know more about your ad performance than most founders at your stage. But if you'd rather have someone do it for you every week, automatically, that's what we built.