Marketing KPIs: the 5 key metrics and the benchmarks to compare against (2026)

Acquiring a new customer costs between 5 and 25 times more than keeping one you already have, according to the Harvard Business Review. That's why a good marketing dashboard isn't the one with the most numbers, but the one that shows how much growth costs and whether that growth is profitable.

These are the five KPIs (key performance indicators) to measure first, with benchmark figures to compare your results.

1. Customer acquisition cost (CAC)

How much it costs, on average, to win a new customer. Add up what you spent on marketing and sales in a period and divide it by the new customers in that period.

Example calculation: if in one month you spend CLP 2,000,000 on advertising and sales salaries and win 80 new customers, your CAC is CLP 25,000.

It's worth calculating it by channel (paid search, social media, email, organic): an overall average can hide a channel that isn't profitable.

2. Customer lifetime value (LTV)

How much money a customer brings in over their whole relationship with the company. Estimate it by multiplying the average order value by the number of purchases per year and by the number of years the customer stays.

LTV only makes sense compared with CAC: if a customer brings in less than it costs to win them, growing faster only grows the loss.

3. Conversion rate, CTR and cost per lead

What percentage of visits or clicks ends in a purchase or a lead. In search advertising you also measure CTR (the share of people who click the ad) and cost per lead.

The WordStream study of 16,446 Google Ads campaigns in the United States (April 2024 to March 2025) gives these all-industry averages:

Google Ads metric	2025 average
CTR (clicks over impressions)	6.66%
Cost per click	US$5.26
Conversion rate	7.52%
Cost per lead	US$70.11

These are U.S. figures, where clicks tend to be more expensive than in Latin America. They work better as a reference for the percentages than for the costs.

4. Email marketing metrics

Email is still one of the cheapest channels for staying in touch with customers. According to Mailchimp's benchmarks (updated December 2023), the average across all its users is:

Open rate35.63%

Click rate2.62%

Unsubscribe rate0.22%

Source: Mailchimp, benchmarks updated December 2023

View the data as a table

Open rate	35.63%
Click rate	2.62%
Unsubscribe rate	0.22%

In e-commerce, the average open rate drops to 29.81% and clicks to 1.74%. Mailchimp warns that open rates may be inflated by Apple Mail's privacy feature, which marks emails as opened even if the person doesn't read them. That's why clicks deserve more weight.

5. Retention rate

What percentage of customers buy again in a period. It's the KPI with the biggest impact on profitability: according to research by Frederick Reichheld of Bain & Company, cited by the Harvard Business Review, increasing retention by 5% can raise profits by 25% to 95%.

The range is wide because it depends on the industry, but the conclusion holds: a returning customer costs far less than a new one.

Summary: what to measure and what to compare it with

KPI	What it answers	Benchmark
CAC	How much does a new customer cost me?	Compare it by channel and against LTV
LTV	How much does a customer bring in over time?	It must be higher than CAC
Google Ads conversion	How many clicks become leads or sales?	7.52% average (WordStream)
Email clicks	How many readers take action?	2.62% average (Mailchimp)
Retention	How many customers come back?	+5% retention = +25% to 95% profits (HBR)