What are metrics and their role in Facebook advertising

Metrics are quantitative data used to evaluate the performance of an ad, such as the number of impressions, click-through rate (CTR), cost per action (CPA) or return on investment (ROI). In other words, metrics are the “language of numbers” that helps marketers see how their ads are performing.

If Facebook Ads is considered a “money printing machine”, then metrics are the dashboard, displaying the status of the entire machine.

• Metrics reflects advertising effectiveness: This is the data that tells you whether your campaign is performing well or not, whether it is achieving its desired reach and conversion goals.
• Metrics show budget “gaps”: By tracking data, you can detect ineffective ads early so you can stop or optimize them in time, avoiding wasting money.
• Metrics are the foundation for optimal decisions: Numbers help marketers know when to increase their budget, try A/B testing, or adjust their targeting, instead of relying on gut feelings.

For example, you run a campaign to sell sneakers. The ad has eye-catching images and emotional content, but the CTR is only 0.2% (much lower than the average of 1.5%). If you don't track CTR, you might think that the campaign is "fine". But in reality, this indicator shows that the ad is not attractive enough or targeting the wrong customer group.

9 most important Facebook Ads metrics

1. Reach

Reach tells you how many unique users saw the ad. This is an index that helps you evaluate the level of brand coverage.

• Different from Impressions: Reach counts people, Impressions counts the number of impressions (the same person can see many times).
• How to read: High Reach proves that the content is widespread enough; Low Reach can be due to the target being too narrow or the creative not being attractive.

When Reach is low, try expanding the audience or try A/B testing the creative.

2. Cost per Action (CPA - Cost per Action)

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

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

If the CPA is too high, review your audience and ad copy. Sometimes just changing the CTA can help reduce CPA drastically.

3. Click-through Rate (CTR – Click-through Rate)

CTR reflects the rate of people clicking on the ad after seeing it.

• Formula: (Number of clicks / number of impressions) x 100%.
• Meaning: High CTR = attractive content, correct target; Low CTR = ad does not create enough motivation to click.

The average CTR on Facebook is about 1.5%. If your CTR is below 0.5%, consider rewriting the headline, changing the image, or tweaking the audience.

4. Cost per Click (CPC)

CPC reflects the average cost per click. This is a familiar indicator to evaluate the effectiveness of budget allocation.

Low CPC is not necessarily good if CTR is low and conversion is poor. Always look at CPC in relation to ROI.

5. Frequency (Frequency) 

Facebook calculates how many times an average person sees an ad.

• Frequency 2 - 3: reasonable.
• Frequency 5+: likely to cause ad fatigue (viewers get bored, skip or report).

6. Profit rate (ROI – Return on Investment)

ROI reflects whether advertising is really profitable or not. This is the core metric to determine business performance, rather than just looking at reach or engagement.

• Formula: ROI = (Revenue – Cost) / Cost.
• ROI > 0: The campaign is profitable. For example: spend 20 million on advertising, earn 35 million → ROI = 75%.
• ROI < 0: The campaign is losing money and needs to be adjusted or paused.

ROI analysis helps businesses avoid falling into the “vanity metrics trap” – beautiful numbers that don’t bring real profits.

7. Engagement

Engagement includes actions such as liking, sharing, commenting, clicking, and saving posts. This is a measure of how much customers are interested in and respond to an ad.

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

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

8. Cost per 1000 impressions (CPM – Cost per Mille)

CPM indicates the amount you have to pay for your ad to be displayed 1,000 times. This is an important indicator to understand the level of competition and distribution efficiency.

• Low CPM often comes with a wide audience, attractive content and little competition.
• High CPM appears when the target is narrow, the market has many competitors bidding or the content is not attractive enough.

For example, a popular product promotion campaign can achieve a low CPM, while real estate advertising often has a high CPM due to fierce competition.

9. Conversions

Conversions is the most important indicator, reflecting the final results of advertising: number of orders, number of completed forms, number of subscriptions sign.

• High conversion proves that the ad, landing page and product operate in sync.
• Low conversion can be due to the ad not being attractive enough, the landing page loading slowly, the form being too complicated or the payment process being inconvenient.

For example: spend 10 million VND on advertising, get 1,000 landing page visits, of which 100 people fill out the registration form → 10% conversion rate. If only 20 people actually buy, you need to optimize the care and closing sale.

To increase conversion, you can't just focus on advertising but need to synchronize the product, landing page experience and sales process..

Additional metrics that are less noticed but extremely useful

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

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

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

How to use metrics to optimize ads?

Metrics are not just dry data, but a “map” that helps you know if you are on the right track or lost. So how to make the most of advertising metrics?

• Define clear goals: Do you need to increase leads, increase revenue or increase brand awareness? Each goal is associated with a different set of metrics .
• Monitor regularly: Don't let the campaign run for 7–10 days before viewing the report. Facebook Ads are constantly changing, so you need to check them daily.
• A/B Testing: Always compare 2–3 versions of creative, headline, or target to find the best option.
• Landing page investment: No matter how good the ad is, if the landing page is not convincing, you will still lose money.
• Use advanced tracking tools: Ads Manager is just the basic step, combine it with specialized tools (e.g. Keitaro Tracker) to track more than 30 detailed metrics.
• Landing page investment: No matter how good the ad is, if the landing page is not convincing, you will still lose money.

Conclude

Running Facebook ads without understanding metrics is like setting sail without a compass. You will spend a lot of money but not know if you are on the right track. Start with basic metrics (Reach, CTR, CPC, Conversions), then upgrade to advanced metrics. Combined with regular data monitoring, your advertising effectiveness will definitely improve significantly.