If you manage online ads and measure your success solely by ROAS (Return on Ad Spend), you are likely missing out on the most important thing—the actual profit of your business.

More and more experienced advertisers are moving away from ROAS to more holistic metrics such as POAS (Profit on Ad Spend), MER, and Lifetime Value. Why? Because ultimately, the goal of any business is not to have impressive numbers on advertising platforms, but to generate real profit.

In this article, we'll look at why ROAS is misleading, what metrics really matter, and how to measure the true profitability of your ads.

Why ROAS doesn't show the whole picture

ROAS is the most popular metric on platforms like Meta and Google. It's easy to calculate:

ROAS = Advertising revenue / Advertising costs

If you spent BGN 1,000 on advertising and generated BGN 5,000 in revenue, your ROAS is 5:1 (or 500%). Sounds great, right?

The problem is that ROAS ignores all other costs in your business:

Cost of goods sold (COGS – Cost of Goods Sold)
Logistics and delivery
Payment system fees (Stripe, PayPal, etc.)
Packaging and labels
Product returns
Team salaries
Other marketing expenses (email marketing, influencer collaborations, SEO)

Real-life example: When a high ROAS hides a loss

Case 1: E-commerce shoe store

Advertising revenue: BGN 50,000
Advertising costs: BGN 10,000
ROAS: 5:1 ✅ (looks great!)

But let's look at the full picture:

Product cost: BGN 25,000
Delivery: BGN 3,000
Commissions (3%): BGN 1,500
Packaging: BGN 1,000
Returns (10%): BGN 5,000

Actual profit:
50,000 – 10,000 – 25,000 – 3,000 – 1,500 – 1,000 – 5,000 = 4,500 BGN.

Profit margin: only 9%With a ROAS of 5:1!

If you don't take all these costs into account, you may think your campaigns are working great, when in fact you're barely breaking even (or even operating at a loss).

What is POAS (Profit on Ad Spend) and why is it more important

POAS (Profit on Ad Spend) is a metric that measures actual profit relative to advertising costs, not just revenue.

POAS = Profit (after all expenses) / Advertising costs

Using the example above:

Profit: BGN 4,500
Advertising costs: BGN 10,000
POAS: 0.45:1 (or 45%)

This means that for every 1 BGN spent on advertising, you earn $0.45 in net profit.

Why POAS is a better metric than ROAS

It reflects the real economics of the business – it sees all costs, not just advertising costs
It helps you make better decisions – you know which products/campaigns are generating real profit
It protects you from the illusion of success high ROAS does not always mean profit
It allows for sustainable scaling – you know how much you can spend without losing money

MER (Marketing Efficiency Ratio): Your holistic metric

Another critical metric that many advertisers underestimate is MER (Marketing Efficiency Ratio)This is the "macro" version of ROAS, which takes into account all marketing costs, not just paid ads.

MER = Total Revenue / All Marketing Expenses

Why MER is important

Platforms such as Meta and Google only show their own contribution. But in reality:

Customers see your ad on Facebook
Then they search for your brand on Google
They hear about you from a friend
They see you on Instagram
Finally, they buy directly from your website

Which channel should get the "credit"? Each of them will say "me!", but the truth is that they all contributed.

MER gives you a realistic picture of the effectiveness of your entire marketing, not just individual channels.

Example of MER

Total revenue for the month: BGN 100,000
Meta advertising costs: BGN 15,000
Google advertising costs: BNG 8,000
Email marketing software: BGN 500
Influencer collaborations: BGN 2,000
Total marketing expenses: BGN 15,000

MER = 100,000 / 25,500 = 3.92

This means that for every $1 spent on marketing (across all channels), you generate $3.92 in revenue.

If Meta shows you a ROAS of 6:1 and Google shows you a ROAS of 4:1, you might think everything is perfect. But a MER of 3.92 tells you that the real effectiveness is lower because there is overlap in attribution and other hidden costs.

CAC, LTV, and Profit Margin: The trio that determines long-term success

In addition to POAS and MER, there are three other critical metrics that every serious advertiser should track:

1. CAC (Customer Acquisition Cost)

CAC = Total marketing costs / Number of new customers

If you spent BGN 10,000 and acquired 200 customers, your CAC is BGN 50.

Why it is important:
You need to know how much a customer costs to understand whether you can profit from them.

2. LTV (LifeTime Value) – The value of a customer over their entire "lifetime"

LTV = Average order value × Number of repeat purchases × Retention period

If your average customer buys 3 times for BGN 100 each time, their LTV is BGN 300.

Why it is important:
If you know your customers buy more than once, you can afford a higher CAC on the first purchase.

3. LTV:CAC Ratio – The ratio between the value of the customer and the cost of acquiring them

The golden rule:

LTV:CAC < 1 – you lose money on every customer
LTV:CAC = 1–3 – you are barely breaking even or have a low profit
LTV:CAC > 3 – a healthy, sustainable business model

If your CAC is BGN 50 and your LTV is BGN 200, your ratio is 4:1 – an excellent result!

Case study: Subscription business

Before optimization:

CAC: 80 BGN
Average monthly subscription fee: 30 BGN
Average retention: 4 months
LTV: 120 BGN
LTV:CAC = 1.5:1 ❌ (we are losing money!)

After optimization (focus on retention and repeat sales):

CAC: BGN 75 (improved creatives, better targeting)
Average monthly fee: BGN 30
Average retention: 9 months (improved service and engagement)
LTV: BGN 270
LTV:CAC = 3.6:1 ✅ (healthy business!)

The difference? Initially, the business was losing money on every customer. After optimisation, it generates a sustainable profit.

How platforms "manipulate" attribution models in their interest

It is important to understand that Meta, Google, and other platforms have a financial interest in showing you the best possible results. They make money when you spend more.

How attribution bias works

Last-click attribution
If a customer sees your ad on Facebook, then searches on Google and makes a purchase, Google will say "this is my sale," while Meta will not count it.
View-through conversions
Meta and Google count sales even if the user only saw the ad (without clicking) and then bought within 1-7 days. This inflates the numbers.
Data modelling on iOS 14.5
Following changes to Apple's privacy policies, platforms use "models" to "fill in the missing data." Sometimes these models are overly optimistic.
Cross-device tracking
If someone sees the ad on their phone but makes a purchase on a computer, it is not always correctly attributed.

What to do

Don't trust the numbers on the platforms 100% — they are always slightly inflated.
Use MER as a "macro check" — if Meta says ROAS is 8:1, but your MER is 3:1, the truth is somewhere in between.
Implement server-side tracking – more accurate data = better decisions
Monitor in Google Analytics or another independent platform – to get an objective point of view

A practical framework for measuring real profit

Here is a step-by-step system that you can implement in your business today:

Step 1: Gather all expenses

Make a list of:

Cost of goods sold (COGS)
Shipping
Packaging
Commissions (Stripe, PayPal, etc.)
Returns
Marketing (all channels)
Salaries (if you have a dedicated marketing team)

Step 2: Calculate Gross Profit

Gross Profit = Revenue – COGS – Logistics – Fees

This is your gross profit before marketing and other operating expenses.

Step 3: Calculate POAS

POAS = (Gross Profit – Marketing Expenses) / Marketing Expenses

This tells you whether advertising brings real profit.

Step 4: Track MER monthly

MER = Monthly Revenue / Monthly Marketing Expenses

Compare MER month over month to see if your efficiency is improving.

Step 5: Analyse by product/campaign

Not all products are equally profitable. Break down the data:

Which products have the highest POAS?
Which campaigns generate the most actual profit?
Are there products that look good on ROAS but are actually losing money?

Step 6: Optimise based on profit, not revenue

Once you know which products/campaigns are generating actual profit:

Allocate more budget to them
Reduce or discontinue products with low POAS
Test ways to improve margins (lower costs, higher prices, better retention)

Conclusion:

In digital marketing, it's easy to be misled by attractive numbers on advertising platforms. But at the end of the day, what really matters is how much money is left in your pocket at the end of the month.

ROAS is a useful metric for campaign optimization, but it should never be your only metric.Switching to POAS, MER, and holistic profitability measurement is the difference between "looking good on the dashboard" and "having real, sustainable profits."

Start tracking these metrics today. You'll be surprised how different reality is from what advertising platforms show you.

Are you ready to move from ROAS to real profit?

If you want to understand the true profitability of your ads and implement a POAS bidding strategy that delivers measurable results, contact me.

From ROAS to Profit: How to Measure the True Profitability of Your Ads