What are metrics and what is their role in Facebook advertising?

Metrics are quantitative data used to evaluate the effectiveness of advertising, such as impressions, click-through rate (CTR), cost per action (CPA), or return on investment (ROI). In other words, metrics are the "language of data" that helps marketers see how their advertising is performing.

Metrics used to evaluate advertising effectiveness (Source: Instapage)

If we consider Facebook Ads as a "money-making machine," then metrics are the dashboard, displaying the overall status of that machine.

• Metrics reflect advertising effectiveness: This data tells you whether your campaign is performing well, and whether it's achieving your desired reach and conversion goals.
• Metrics reveals budget "gaps": By tracking data, you can detect ineffective ads early so you can stop or optimize them in time, avoiding wasted money.
• Metrics are the foundation for optimal decision-making: Numbers help marketers know when to increase budgets, conduct A/B testing, or adjust targets, instead of relying on intuition.

For example, you're running a campaign to sell sneakers. The ads have eye-catching visuals and engaging content, but the CTR is only 0.2% (much lower than the average of 1.5%). Without tracking the CTR, you might think the campaign is doing well. But in reality, this metric indicates that the ads aren't engaging enough or that you're targeting the wrong customer segment.

9 most important Facebook Ads metrics

1. Reach

Reach tells you how many unique users have seen your ad. This metric helps you assess your brand's reach.

• Unlike Impressions, Reach counts the number of people, while Impressions count the number of times the image is displayed (the same person can see it multiple times).
• How to interpret: High reach indicates content has the potential to spread widely; low reach may be due to a narrow target audience or unappealing creativity.

When reach is low, try expanding the audience or experimenting with A/B testing for creatives.

2. Cost per Action (CPA)

CPA shows how much each action (purchase, form submission, registration, etc.) costs.

Formula for calculating Cost per Action

• Formula: Total advertising cost / number of actions achieved.
• Meaning: The lower the CPA, the more effective the advertisement.

If your CPA is too high, review your target audience and ad copy. Sometimes, simply changing the CTA can significantly lower your CPA.

3. Click-through Rate (CTR)

CTR reflects the percentage of people who click on an advertisement after seeing it.

• Formula: (Number of clicks / Number of impressions) x 100%.
• Meaning: High CTR = engaging content, correct targeting; Low CTR = ad doesn't generate enough click-through motivation.

The average CTR on Facebook is around 1.5%. If your CTR is below 0.5%, consider rewriting your headline, changing your image, or refining your target audience.

4. Cost per Click (CPC)

CPC reflects the average cost per click. This is a familiar metric for evaluating the effectiveness of budget allocation.

A low CPC isn't necessarily good if the CTR is low and conversions are poor. Always consider CPC in relation to ROI.

5. Display Frequency

Facebook calculates the average number of times a person sees an ad.

• Frequency of 2-3: reasonable.
• Frequency of 5+: easily causes ad fatigue (viewers get bored, skip, or report).

Ad fatigue occurs when content doesn't change (Source: Charlie Lawrance)

6. Return on Investment (ROI)

ROI reflects whether advertising is actually generating profit. This is a core metric for determining business effectiveness, rather than just looking at reach or engagement.

• Formula: ROI = (Revenue – Costs) / Costs.
• ROI > 0: The campaign is profitable. For example: spending 20 million on advertising, earning 35 million → ROI = 75%.
• ROI < 0: Campaign is losing money and needs adjustment or suspension.

ROI analysis helps businesses avoid falling into the "vanity metrics trap"—numbers that look good but don't reflect real profits.

7. Engagement

Engagement includes actions such as liking, sharing, commenting, clicking, and saving posts. This is a measure of customer interest and response to advertising.

• High engagement creates social proof, making others trust the product or brand more.
• Advertising platforms often prioritize organic distribution for highly engaging content, thereby reducing advertising costs.

The higher the interaction, the more effective the advertising.

For example, a summer drink advertisement video that receives thousands of comments asking about prices and sharing experiences will go viral quickly without requiring a large additional budget.

8. Cost per 1000 impressions (CPM)

CPM indicates the amount you pay for an ad to be displayed 1,000 times. This is an important metric for understanding the level of competition and the effectiveness of ad distribution.

• Low CPM is often associated with a broad audience, engaging content, and less competition.
• High CPM occurs when the target audience is narrow, the market has many competitors bidding, or the content is not attractive enough.

For example, a promotional campaign for a mass-market product might have a low CPM, while real estate advertising typically has a high CPM due to intense competition.

9. Conversions

Conversions are the most important metric, reflecting the final results of advertising: the number of orders, the number of completed forms, and the number of registrations.

• High conversion rates indicate that advertising, landing pages, and products are working in sync.
• Low conversion rates can be caused by unappealing ads, slow-loading landing pages, overly complex forms, or inconvenient payment processes.

For example: spending 10 million VND on advertising, resulting in 1,000 landing page visits, of which 100 people filled out the registration form → conversion rate 10%. If only 20 people actually made a purchase, you need to optimize the customer service and sales closing process.

To improve conversions, you can't just focus on advertising; you need to synchronize the product, landing page experience, and sales process.

These additional metrics are often overlooked but extremely useful.

In addition to the 9 core metrics, Facebook also provides many advanced metrics:

• Cost per Messaging Reply: measures the cost per response in Messenger.
• Cost per Page Like: the cost to get one more page like.
• Video Metrics: 10-second views, ThruPlays, Average Watch Time.
• Blocked Messaging Connections: the number of times a message has been blocked by a user after sending it.

These metrics are especially important for businesses running Messenger ads, event ads, or video ads.

How can I use metrics to optimize my ads?

Metrics are not just dry data; they are the "map" that helps you know if you're on the right track or lost. So how can you leverage metrics to optimize your advertising?

• Define your goals clearly: Do you need to increase leads, revenue, or brand awareness? Each goal is associated with a different set of metrics.
• Monitor regularly: Don't wait 7–10 days after your campaign starts to check the report. Facebook Ads are constantly changing, so you need to check daily.
• A/B Testing: Always compare 2–3 versions of the creative, headline, or target to find the best option.
• Investing in landing pages: No matter how good the advertising is, if the landing page isn't persuasive, you'll still lose money.
• Utilize advanced tracking tools: Ads Manager is just the basic step; combine it with specialized tools (e.g., Keitaro Tracker) to track over 30 detailed metrics.
• Investing in landing pages: No matter how good the advertising is, if the landing page isn't persuasive, you'll still lose money.

GTG CRM's treasure trove of landing page templates

Conclude

Running Facebook ads without understanding metrics is like sailing without a compass. You'll waste a lot of money without knowing if you're heading in the right direction. Start with the basics (Reach, CTR, CPC, Conversions), then move on to more advanced metrics. Combined with regular data monitoring, your ad performance will definitely improve significantly.