5 Key Marketing Metrics Every Junior Marketer Should Know

In your first marketing interview, the hiring manager won’t just ask if you "like social media." They will ask how you measure the success of a campaign. If you answer with "likes" or "followers," you’re showing them you're still thinking like a student.

To impress, you need to focus on performance metrics. These five KPIs (Key Performance Indicators) are the heartbeat of modern marketing.

1. Customer Acquisition Cost (CAC)

What it is: The total cost of sales and marketing efforts divided by the number of new customers acquired. Why it matters: If it costs you $50 to get a customer but they only spend $20 on your product, your business is losing money. Junior marketers who understand CAC are seen as "business-minded" rather than just "creative."

2. Conversion Rate (CR)

What it is: The percentage of visitors who complete a desired action (like signing up for a newsletter or buying a product). Why it matters: Conversion rate is the ultimate "BS detector." You can have a million website visitors, but if your conversion rate is 0%, your marketing isn't working. In 2026, a healthy benchmark for a lead-generation page is roughly 2.2% to 3%.

3. Engagement Rate (The GA4 Way)

What it is: The percentage of "Engaged Sessions" compared to total sessions. Why it matters: As we discussed in the GA4 guide, an engaged session means someone stayed for more than 10 seconds or interacted with your site. A high engagement rate proves that your content is actually relevant to the people clicking on it.

4. Return on Ad Spend (ROAS)

What it is: The amount of revenue a company receives for every dollar spent on an advertising source. Why it matters: If you spend $1 on Google Ads and get $5 back in sales, your ROAS is 5:1. This is the primary metric used to evaluate the efficiency of SEM (Paid Search) campaigns.

5. Customer Lifetime Value (CLV)

What it is: The total revenue a business can expect from a single customer account throughout the business relationship. Why it matters: It’s almost always cheaper to keep an existing customer than to find a new one. High-performing marketing teams focus on CLV because it leads to long-term, sustainable growth.