Programmatic advertising can sometimes feel like a whirlwind of acronyms and numbers. CPM, CTR, CPC—what do they really mean, and which ones do you need to pay attention to?
This matters even more when you’re using a self-serve advertising platform like a DSP (what’s a DSP? Understand the basics of digital advertising is our recent blog), and don’t have the expertise of an agency to rely on. It’s common to get lost in the maze of metrics that platform reports generate, making it challenging to fully understand your campaign’s performance, even when working with an agency.

For small and medium- sized businesses (SMBs), understanding advertising metrics is critical because they often operate with tighter budgets and limited resources. Unlike large brands that have the luxury of big budgets and dedicated agencies to manage their campaigns, SMBs need to be more strategic and efficient in their ad spend.

This breakdown will explain key metrics and how they help optimize campaigns without data scientists.

Impressions: Your First Port of Call

First things first—are people even seeing your ad? Impressions track how often your ad is displayed on a screen.Think of impressions as the potential for attention, not a guarantee. Remember, a single user can register multiple impressions if the ad appears several times on the same page.

When it comes to programmatic advertising, a focus on capturing a good number of impressions is fairly important. After all, no one can interact with your ad if they don’t see it at all.

Pro-tip: Impressions are a function of getting a combination of channels, segments, messaging, budgets and audiences right, among other things. Good news is, you can start small, test different combinations, and scale what works best for your business.

Clicks and CTRs: The OG Engagement Metrics

Clicks—the metric we all know and love. Whether it’s driving traffic to a landing page or collecting leads, clicks tell you that your ad is working. CTR (click-through rate) gives you another perspective showing you the percentage of people who clicked on your ad after seeing it.

So if you had, say 2 clicks on your ad. Good? Bad? We don’t know until we know more, and that’s where the CTR comes in.

CTR is the number of clicks your ad generated divided by the total number of times it was shown.

So suppose those 2 clicks came from 1,000 impressions. That’s a 0.2% CTR. Now suppose you see that those 2 clicks came from 200 impressions. That’s a 1.0% CTR, which is considered good in the programmatic world.

CTR can help you gauge the effectiveness of your creative and targeting. If it’s low, it might be time to rework your message or adjust your audience. Different platforms can be expected to deliver different CTRs. Search (PPC) campaigns, for instance, typically have higher CTRs than programmatic display campaigns.

Pro-tip: CTR is a good first indicator of performance, but don’t obsess over it. A high CTR with no conversions might just mean your targeting is off, attracting people who click but don’t convert. SMBs should balance CTR insights with conversion data to ensure real business impact.

Conversions: The Endgame

Conversions are the ultimate measure of success for many digital ad campaigns. Whether it’s a product sale, newsletter signup, or any other desired action, conversions track the number of users who complete that goal.

This metric is highly customizable based on your campaign objectives. You need to figure out what a ‘conversion’ means for you and your campaign.

Pro-tip: Pair conversion data with your CTR,channels, VCR, creatives, etc to identify which elements of your campaigns are actually delivering results.

Post-View Conversions: Measuring Influence Beyond Clicks

Post-view conversions capture users who saw your ad but didn’t click on it—yet still converted later. This metric highlights the value of display and video ads in creating awareness and influencing customer decisions indirectly.

While these conversions don’t involve immediate action, they demonstrate the power of impression-based advertising in the customer journey.

Pro-tip: For SMBs with brand awareness goals, post-view conversions can provide critical insights into how your ads influence long-term purchasing decisions.

Post-Click Conversions: Tracking Immediate Impact

Post click conversions measure how often users see your ad, click on it, and convert (eg, buy a product or fill out a form) during that same visit. This metric is particularly useful for tracking users who convert immediately, without requiring additional nurturing.

Pro-tip: Post-click conversions are great for assessing the direct impact of your ads and helps you identify campaigns that are driving instant results

Last-Click Conversions: The Common but Flawed Metric

Last-click conversions are one of the most widely used metrics in tools like Google Analytics. This metric attributes the entire conversion to the last interaction a customer had with your ad before converting.

While last-click conversions are easy to track, they can be misleading. A customer’s journey typically includes multiple touchpoints—display ads, audio ads, emails, retargeting ads, and more—that contribute impressions and clicks that could be leading to the final conversion. Relying solely on last-click data ignores the value of upper- and mid-funnel efforts that build awareness and consideration.

Retargeting campaigns, in particular, can skew ROI calculations when evaluated through a last-click lens. They often target users who are already drawn to your brand or website due to earlier interactions from other channels, giving retargeting credit for conversions it didn’t initiate.

Pro-tip: Use last-click conversions as just one piece of the puzzle and complement it with metrics like post-view conversions or multi-touch attribution to get a more accurate picture of your campaign’s performance.

Cost Per Acquisition (CPA): Minimizing Your Ad Spend

Cost Per Acquisition (CPA) tracks how much you’re spending to achieve a defined goal, like a conversion. It’s calculated by dividing the total campaign spend by the number of customers gained.

CPA gives you a clear understanding of your campaign’s efficiency. Lowering CPA while maintaining quality leads or conversions is the holy grail for programmatic advertisers.

Pro-tip: Start with small budgets and regularly analyze CPA across different campaigns to find the sweet spot between cost and quality for your business.

The Ultimate Trick? Keep Learning

Getting your programmatic campaigns performing well takes time and effort. Understanding the metrics that you need to pay attention to is a critical part of the puzzle here. As you get more familiar with the way digital ads are measured and analyzed, you will be able to make better decisions around targeting, audiences and platforms that will then lead you to better campaign outcomes.