The Facebook Ads Glossary Every Ecommerce Seller Needs to Know

Campaign Structure Terms

Campaign

The top level of your Facebook ad structure. A campaign contains one or more ad sets and is defined by a single objective — what you want Facebook to optimize for. Common objectives for ecommerce include Sales (purchase conversions), Traffic (website visits), and Leads (email signups).

Ad Set

The middle level. An ad set defines your audience (who sees the ads), your budget, your schedule, and your placements. You can run multiple ad sets within one campaign to test different audiences.

Ad

The bottom level — the actual creative your audience sees. One ad set can contain multiple individual ads with different images, copy, or headlines, allowing you to test creative variations against the same audience.

Audience Terms

Custom Audience

An audience you create from your own data — your customer email list, your website visitors (via the Pixel), your social media engagers, or your app users. Custom Audiences are usually your most responsive and lowest-cost audiences.

Lookalike Audience

An audience Facebook creates by finding users who are statistically similar to an existing Custom Audience. A 1% Lookalike from your past customers means Facebook finds the 1% of your target country's users most similar to the people who have already bought from you.

Cold Audience

Any audience that has had no prior interaction with your brand. Interest-based audiences and Lookalike Audiences targeting new people are cold audiences.

Warm Audience

An audience that has already interacted with your brand — website visitors, video viewers, social media engagers. These people are more likely to convert than cold audiences.

Performance Metric Terms

Impressions

The total number of times your ad was displayed, including multiple times to the same person.

Reach

The number of unique people who saw your ad at least once. Reach is always less than or equal to impressions.

Frequency

The average number of times each person in your audience has seen your ad. Calculated as Impressions ÷ Reach. When frequency climbs above 3–4, ad fatigue often sets in.

Click-Through Rate (CTR)

The percentage of people who saw your ad and clicked on it. Calculated as Clicks ÷ Impressions × 100. A higher CTR generally indicates more relevant creative for your audience.

Cost Per Click (CPC)

The average amount you pay each time someone clicks your ad. Lower CPC means you're getting more website traffic for your money.

Cost Per Mille (CPM)

The cost per 1,000 impressions — how much it costs to show your ad to 1,000 people. CPM varies based on audience competitiveness, season, and ad quality.

Conversion Rate

The percentage of people who clicked your ad and then completed your desired action (usually a purchase). Calculated as Purchases ÷ Clicks × 100.

Cost Per Purchase (CPP)

The average amount spent in ads to generate one sale. This is often your most important metric if your goal is driving product sales.

Return on Ad Spend (ROAS)

Revenue generated divided by ad spend. A 4x ROAS means for every $1 spent on ads, you generated $4 in revenue. Note that ROAS measures revenue, not profit — you need to factor in your margins to determine actual profitability.

Average Order Value (AOV)

The average amount customers spend per order. Increasing AOV through bundles or upsells allows you to spend more to acquire each customer while maintaining profitability.

Customer Acquisition Cost (CAC)

The total cost of acquiring one new customer, including all marketing and advertising spend. Lower CAC means more efficient growth.

Customer Lifetime Value (LTV or CLV)

The total revenue — or profit — you expect to generate from a customer over the entire time they buy from you. Higher LTV allows you to justify higher acquisition costs.

Technical Terms

Facebook Pixel (Meta Pixel)

A small piece of tracking code you install on your website. It tracks visitor behavior and reports back to Facebook, enabling conversion tracking, retargeting, and Lookalike Audience creation.

Learning Phase

The period after launching a new campaign when Facebook's algorithm is testing different audiences, placements, and times to find the best delivery strategy. Campaigns in the learning phase typically show less consistent results. Most campaigns exit the learning phase after around 50 conversion events.

Advantage+ Placements

Facebook's automated placement option that runs your ads across all available placements and distributes budget to wherever it performs best. Recommended for most advertisers, especially when starting out.

Campaign Budget Optimization (CBO)

A setting that lets Facebook automatically distribute your campaign budget across all ad sets in real time, allocating more to the best-performing audiences. An alternative is setting individual budgets at the ad set level.

Ad Fatigue

The decline in ad performance that occurs when an audience has seen the same ad too many times. Indicated by rising frequency, falling CTR, and increasing cost per result.

Social Proof

Evidence that other people have bought or positively reviewed your product — reviews, ratings, customer counts, testimonials. Social proof in ads builds trust with skeptical new buyers.

UTM Parameters

Tags added to your ad URLs that track the source and campaign details of each click in your analytics platform. Essential for accurate attribution when cross-referencing Facebook data with Google Analytics or your store's analytics.

Attribution Window

The time period Facebook uses to credit a conversion to an ad. A 7-day click, 1-day view attribution window means Facebook will credit your ad if a purchase happens within 7 days of a click or 1 day of a view.

Ready to Put These Terms Into Practice?

Understanding the terminology is one thing — building campaigns that move those metrics in the right direction is another. Stirling helps ecommerce and DTC product sellers create the high-quality static Facebook ad creative that improves CTR, lowers CPC, drives purchases, and delivers the ROAS that makes your business grow. Start building better-performing ads with Stirling and put this knowledge to work.