ACoS (Advertising Cost of Sales)


What Is ACoS?

ACoS, or Advertising Cost of Sales, is a key metric in online advertising that calculates the ratio of advertising expenditure to sales revenue generated. It helps e-commerce businesses measure the efficiency and profitability of their ad campaigns on platforms like Amazon. ACoS represents the percentage of sales revenue spent on advertising, allowing businesses to optimize their advertising strategies and maximize their return on investment.

By analyzing the ACoS, businesses can determine whether their advertising campaigns are profitable or not. A low ACoS indicates that the advertising spend is generating a higher return on investment, as the sales revenue outweighs the advertising cost. On the other hand, a high ACoS suggests that the advertising campaigns are not as efficient, and the cost of acquiring customers through advertising is eating into the profit margin.

By monitoring and optimizing the ACoS, businesses can fine-tune their advertising strategies, adjust their budget allocation, and focus on campaigns that yield higher returns. It helps businesses evaluate the effectiveness of different advertising channels, keywords, and campaigns, allowing them to make data-driven decisions to improve their advertising performance.

Overall, ACoS is a crucial metric for e-commerce businesses engaged in online advertising, as it provides valuable insights into the profitability and efficiency of their ad campaigns on platforms like Amazon.

How to Calculate ACoS

To calculate ACoS (Advertising Cost of Sales), you use the following formula:

ACoS = (Advertising Spend / Sales Revenue) x 100. 

First, determine the total advertising spend for a specific period. Next, calculate the sales revenue generated during that same period. Divide the advertising spend by the sales revenue, then multiply the result by 100 to get the ACoS percentage. 

For example, let’s say a business spent $1,000 on advertising and generated $5,000 in sales revenue. The ACoS would be:

ACoS = ($1,000 / $5,000) x 100 = 20%

This means that for every dollar spent on advertising, the business generated $5 in sales revenue, with 20% of the revenue being used to cover the advertising cost.

ACoS is an important metric in digital advertising, particularly for businesses engaged in online sales. It allows companies to evaluate the effectiveness of their advertising campaigns and understand the return on investment (ROI) generated from their advertising spend.

In addition to ACoS, businesses should also consider other factors such as customer lifetime value (CLV) and return on ad spend (ROAS) when evaluating their advertising efforts. These metrics provide a more comprehensive understanding of the value generated from advertising and help businesses make data-driven decisions to achieve their marketing goals.

Good and Bad ACoS

A good ACoS (Advertising Cost of Sales) would reflect a profitable advertising campaign, where the advertising spend is reasonable in relation to the revenue generated. For example, if a business spends $100 on advertising and generates $500 in sales revenue, the ACoS would be 20%. 

On the other hand, a bad ACoS would indicate poor efficiency or inefficiency in ad spend. For instance, if the same business spends $500 on advertising but only generates $100 in sales revenue, the ACoS would be 500%. In this case, the business would need to reassess their advertising strategy to improve profitability and reduce wasted ad spend.

Another important aspect to consider when evaluating ACoS is the industry and competitive landscape. Different industries have varying profit margins and cost structures, which can influence what is considered a good or bad ACoS. For instance, a business in a highly competitive industry with low-profit margins may have a higher ACoS threshold compared to a niche market with high-profit margins.

It’s also essential to analyze ACoS in conjunction with other performance metrics, such as conversion rate, average order value, and customer lifetime value. A low ACoS may not always be desirable if it’s accompanied by low conversion rates or small average order values. In such cases, businesses need to strike a balance between increasing their ACoS to drive more sales while maintaining healthy profit margins.

Furthermore, it’s crucial to consider the customer acquisition costs (CAC) and lifetime value (LTV). While ACoS focuses on the cost of sales from advertising, CAC takes into account all costs associated with acquiring a new customer, including marketing and sales expenses. Comparing ACoS to the LTV helps determine whether a business is acquiring profitable customers. If the LTV exceeds the ACoS, it indicates profitability in the long run.

How to Reduce ACOS?

To achieve a lower ACOS, it is important to focus on optimizing targeting, improving ad creative, analyzing and optimizing campaigns, and diversifying advertising channels. Let’s dive deeper into each area:

1. Optimizing Targeting:

Refining your targeting is crucial to reaching the right audience. Start by reviewing and refining your keywords, ensuring they are highly relevant to your products or services. Use keyword research tools and analytics data to identify high-performing keywords and weed out irrelevant ones. Additionally, consider adjusting demographics and interests targeting options to effectively reach your target audience.

2. Improving Ad Creative:

Compelling ad creative will capture attention and drive conversions. Craft engaging and persuasive ad copy that highlights the unique selling points of your products or services. Use clear and concise messaging, appealing visuals, and persuasive calls-to-action. Regularly test different ad variations to identify what resonates best with your audience and optimize your creative accordingly.

3. Analyzing and Optimizing Campaigns:

Regularly monitor and analyze the performance of your campaigns. Track metrics such as click-through rate (CTR), conversion rate (CR), and return on ad spend (ROAS) to identify areas for improvement. Adjust your bids and budgets based on performance data to allocate your ad spend effectively. Split testing different strategies and targeting options can help identify what works best for your campaigns. Continuously refine and optimize your campaigns to maximize their ROI.


ACoS is a metric used in online advertising, specifically in platforms like Amazon and Google Ads, to determine the cost of acquiring a sale. It is calculated by dividing total advertising spend by the sales generated from those ads and expressed as a percentage.


Viktoria Arsenteva

Marketing Manager at Lira Agency. I enjoy creating valuable and informative content for our clients and visitors. I spend my free time reading books on marketing and psychology.