By Ted Gibson — RippleEffect
Total advertising cost of sale is your total ad spend divided by your total sales, organic sales included, which makes it a truer read on what advertising costs you than ACOS, since ACOS only sees the sales the ads themselves touched. There is no single good number. The published benchmarks put good anywhere between 5% and 20%, they contradict each other, and none of them cites a study, so the answer worth having comes from your own margin rather than from someone else's table.
The published benchmarks disagree with each other
It is worth seeing how wide the spread is. NivoAds puts 0 to 10% as excellent and 10 to 20% as good. Canopy Management calls 5 to 10% low, 10 to 15% moderate and 15 to 25% high. Isaac Gross of IG PPC writes that healthy ongoing ad spend lands somewhere around 8 to 15% of sales. Perpetua declines to give a figure at all, on the grounds that TACOS varies with marketplace, goals, ad types, seasonality, competition and price.
Read those together and 18% is simultaneously good and high depending on whose page you landed on. None of them cites a study, because there is not one to cite. They are practitioner opinion, which is useful as long as you read it that way. What the spread tells you is that TACOS only means something next to your own economics.
Work out your own ceiling before borrowing anyone else's
The limit has nothing to do with your category and everything to do with your P&L. Take your gross margin after Amazon's fees and cost of goods, subtract the net margin you actually need, and what is left is the most you can spend on advertising before growth starts costing you money. A brand at 55% gross margin targeting 25% net can carry a much higher TACOS than one at 30% gross, and no published range knows which of those you are. The arithmetic is currency neutral, so it reads the same whether your account does £50,000 or $50,000 a month.
Stage matters as much as margin. A launch should run a deliberately high TACOS, because you are buying rank you intend to hold organically later, and the number should fall as organic sales carry more of the total. MUUSH, our second case study, shows that shape: zero to profitable in under six months, with TACOS down 12% and sales up 126% in Q1 2026 against the quarter before.
A worked example, and why the growth number goes next to it
A falling TACOS on flat sales is rarely an achievement, because the usual cause is simply less advertising. A rising TACOS during fast growth can be exactly right. On our headline case study the figure held at 14.6% while revenue more than doubled, and advertising return finished 44% above the 2025 category average of 1.7. Neither of those numbers means much alone. Quoted together they say the efficiency survived the growth, which is the only version of a good TACOS worth paying for.
If you want a read on your own number, our free account audit separates the advertising that is buying rank from the advertising that is paying for sales you would have made anyway. That distinction is usually what a confusing TACOS is hiding. What the work costs afterwards is published.