Customer Acquisition Cost: What It Is & How Marketers Reduce Costs

Customer acquisition cost (CAC) is one of the most important metrics in marketing. It tells you how much your business spends to acquire a new customer and serves as a key indicator of a company’s growth efficiency.

As advertising costs rise, privacy regulations limit visibility, and competition intensifies across digital channels, many ecommerce brands are seeing CAC increase year after year. The challenge isn't simply spending more on ads. It's understanding what's driving acquisition costs higher and identifying the strategies that improve efficiency without sacrificing growth.

In this guide, we'll explore what CAC marketing is, why customer acquisition costs keep rising, and how leading ecommerce brands are adapting.

What is CAC in marketing?

Customer acquisition cost (CAC) measures the total cost required to acquire a new customer. It includes expenses such as:

• Advertising spend
• Agency fees
• Marketing software
• Creative production
• Salaries and commissions
• Promotional campaigns

CAC can be calculated using the following formula:

CAC = total sales and marketing costs / number of new customers acquired

For ecommerce brands, CAC is one of the most important metrics because it directly impacts profitability, cash flow, and long-term growth.

The importance of CAC

CAC helps businesses understand how efficiently they’re turning marketing and sales investments into new customers. Tracking CAC can help companies:

• Evaluate the effectiveness of marketing and advertising campaigns.
• Determine whether customer acquisition efforts are financially sustainable.
• Compare the performance of different marketing channels.
• Identify opportunities to improve profitability and reduce costs.
• Measure CAC alongside customer lifetime value (LTV) to understand whether customers generate enough revenue to justify acquisition costs.

While CAC is an important metric on its own, it’s often most valuable when analyzed alongside other performance indicators, particularly LTV, retention rate, and return on investment (ROI).

Why CAC keeps rising

Paid customer acquisition costs (CAC) have been climbing steadily for years, squeezing profit margins for even the most efficient ecommerce brands. In fact, in July 2025, Meta reported that the average price per ad had increased by 9% year-over-year. 

To better understand what’s really driving this trend, we spoke to Lolita Petrossov, founder and CEO of Evestar, a full-service ecommerce agency trusted by brands of all sizes.

According to Petrossov, rising CAC  isn’t the result of a single trend. Instead, multiple market forces are colliding simultaneously.

“There’s real inflation in digital advertising. CPMs have increased about 10% year-over-year. At the same time, competition has exploded. More brands are entering paid channels, all fighting for the same attention. You can’t just show up anymore; you have to stand out, and that costs more.”

Compounding the issue is the rapid evolution of acquisition tactics. The rise of social commerce, the tightening grip of privacy regulations, and shifting consumer behaviors have made many traditional growth strategies less effective. Brands today are being pushed toward more creative, data-driven, and expensive ways to stay visible.

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CAC vs. CPA: What's the difference?

Customer acquisition cost (CAC) and cost per acquisition (CPA) are often used interchangeably, but they measure different things.

CPA measures the cost of a specific action, such as a form submission, email signup, or purchase, while CAC measures the total cost of acquiring an actual customer across all marketing and sales efforts.

For example, a campaign may generate a low CPA by driving inexpensive leads, but if those leads fail to convert into paying customers, overall CAC remains high.

For ecommerce marketers focused on profitability, CAC is generally the more meaningful metric.

Rising CAC impacts more than marketing

When acquisition costs spike, it doesn’t just dent your ad budget. It reshapes the entire business model.

“Profitability shrinks, putting pressure on every part of the business,” Petrossov said. “A lot of essential metrics start moving in the wrong direction if CAC isn’t managed early.”

But according to Petrossov, the larger issue often lies beneath the surface.

“High CAC often masks deeper measurement and attribution issues. Brands rely too much on in-platform ROAS, which is inflated due to attribution windows and platform bias. It looks healthy on paper, but once you factor in contribution margin or true lifetime value, it’s not sustainable.”

This illusion of profitability creates a dangerous cycle: brands continue scaling campaigns that appear profitable within ad platforms, only to discover later that actual business performance doesn't support the investment.

The hidden drivers of high CAC

While rising ad costs contribute to higher acquisition expenses, many brands overlook operational issues that make CAC even worse.

Anonymous website traffic

Most ecommerce websites convert only a small percentage of visitors. The vast majority leave without identifying themselves, creating a significant blind spot for marketers trying to improve acquisition efficiency.

Without understanding who these visitors are, brands lose opportunities to retarget, personalize experiences, and recover revenue without website visitor tracking tools.

Attribution gaps

As privacy regulations evolve and third-party tracking becomes less reliable, marketers face increasing difficulty determining which channels actually drive conversions.

This often results in the budget being allocated inefficiently.

Poor Customer Data

Incomplete customer profiles limit audience targeting, personalization, and lifecycle marketing efforts.

When marketers lack accurate customer data, acquisition campaigns become less efficient and more expensive.

How smart brands are reducing CAC

The brands that are strategically navigating high ad costs aren’t just spending more—they’re  diversifying, optimizing, and investing in content, better systems, and stronger customer relationships.

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“The pattern we see is clear: brands that invest in their content engine, from UGC to testimonials to native ads, perform better,” she said. “It’s not about looking polished. It’s about looking authentic.”

Top-performing brands are focusing on:

• User-generated content (UGC)
• Conversion rate optimization (CRO)
• Creator partnerships
• Customer testimonials
• Channel diversification and reallocation
• Full-funnel optimization
• Customer retention

Beyond creative strategy, leading performers are rebalancing their channel mix. Platforms like TikTok Shop have created lower-cost paths to acquisition for brands that understand how to engage authentically.

Creative testing: the new CAC control

As acquisition costs continue rising, creative testing has become one of the most important competitive advantages.

“Brands that don’t understand how creatives work, and don’t produce hundreds of variations, won’t survive. Testing and iteration are fundamental now. The market rewards adaptability.”

This adaptability also extends beyond content to data and measurement. With privacy changes disrupting pixel tracking, brands are increasingly turning to first-party data and advanced analytics.

Successful brands build testing frameworks that continuously evaluate:

• New creative concepts
• Messaging angles
• Offers
• Landing pages
• Audience segments

Instead of relying on a handful of winning ads, they constantly search for the next performance breakthrough.

Why retention is the most effective CAC lever

One of the biggest mistakes brands make is treating acquisition and customer retention as separate functions. In reality, retention marketing strategies directly impact acquisition economics. The more revenue generated from existing customers, the more flexibility brands have when acquiring new ones.

While acquisition is vital, Petrossov emphasized that retention is what sustains growth:

“The real unlock is in your owned channels, email, SMS, and your customer database. When retention improves, your front-end CAC can go up and you’ll still stay profitable.”

Brands that invest heavily in email marketing, SMS marketing, loyalty programs, customer lifecycle marketing, and retention campaigns often achieve stronger profitability even when acquisition costs continue rising.

This is why many ecommerce operators evaluate CAC alongside lifetime value (LTV).

How identity resolution helps Lower CAC

As customer acquisition becomes more expensive, identifying and activating existing demand becomes increasingly valuable.

This is where data-driven tools like Tie make a measurable difference, helping brands convert anonymous visitors, enrich first-party data, and re-engage high-intent shoppers who might otherwise be lost.

Identity resolution allows marketers to:

• Identify anonymous website visitors
• Improve retargeting match rates
• Build richer customer profiles
• Improve attribution accuracy
• Recover lost revenue opportunities

As signal loss increases, these capabilities become critical for maintaining acquisition efficiency. Petrossov points to several effective strategies:

• Capture cross-device signals using Tie.
• Leverage Tie’s identity network, which can de-anonymize over 54% of high-value anonymous traffic using opt-in data from 1,000+ sources.
• Implement AI-driven attribution and incrementality testing to reveal true ROI.

“Brands can’t rely on platform data alone anymore,” she added. “It’s about smarter measurement, using tools that connect data across systems to understand what’s really driving growth.”

Beyond paid: The shift to full-funnel growth

Ecommerce growth is no longer about mastering Meta and Google alone. The brands that scale sustainably are taking a full-funnel approach, acquiring efficiently, converting faster, and retaining longer.

“Just running Meta and Google ads won’t save your business anymore,” Petrossov said. “The game’s gotten harder. You have to generate traffic from multiple sources and work on retention as aggressively as you do on acquisition.”

Her advice to brands is simple but non-negotiable:

• Build a great product.
• Double down on content.
• Excel in full-funnel marketing.
• Adapt constantly.

“Digital marketing is a moving target. The brands that keep growing are the ones that evolve faster than the market.”

Ready to turn rising CAC into an advantage?

Rising paid acquisition costs don’t have to mean shrinking profits. The smartest brands are using this pressure as fuel, tightening their data, refining their creative, and deepening customer relationships to build profitability that lasts.

With the right systems in place, acquisition costs become a metric you control, not fear. 

At Tie, we help ecommerce teams identify high-intent visitors, reconnect with lost shoppers, and recover revenue that would’ve otherwise leaked out of the funnel.

See how Tie helps ecommerce brands convert more visitors into customers. Book a demo.