Digital advertising has developed a complex vocabulary of acronyms, metrics, and concepts that can be overwhelming for newcomers and occasionally unclear even for experienced practitioners. This comprehensive glossary covers the essential terms every media buyer, performance marketer, and digital advertiser needs to know — organized by category for easy reference.
Pricing and Bidding Terms
CPM (Cost Per Mille): Cost per 1,000 impressions. The standard pricing model for display, video, and awareness advertising. A $10 CPM means you pay $10 for every 1,000 times your ad is shown.
CPC (Cost Per Click): Cost per click on your ad. The dominant pricing model for search advertising. You pay only when someone clicks, regardless of how many times the ad is shown.
CPA (Cost Per Acquisition): Cost to acquire one conversion — a purchase, lead, signup, or other defined action. The primary metric for performance campaigns.
CPL (Cost Per Lead): The specific cost to acquire one lead. Common in B2B and service-based advertising.
eCPM (Effective CPM): The equivalent CPM for a CPC or CPA campaign — useful for comparing costs across different pricing models.
tROAS (Target ROAS): A bidding strategy that tells Google's algorithm to optimize for a specific return on ad spend ratio.
Performance Metrics
CTR (Click-Through Rate): The percentage of people who see your ad and click on it. Calculated as clicks divided by impressions.
CVR or CR (Conversion Rate): The percentage of visitors or clicks that complete the desired action. Calculated as conversions divided by clicks.
ROAS (Return on Ad Spend): Revenue generated per dollar of ad spend. A ROAS of 4x means $4 of revenue for every $1 spent on ads.
LTV or CLV (Lifetime Value / Customer Lifetime Value): The total revenue expected from a customer over their entire relationship with your business.
MER (Media Efficiency Ratio): Total revenue divided by total ad spend — a broader, more business-level view of advertising efficiency than campaign-level ROAS.
Audience and Targeting Terms
ICP (Ideal Customer Profile): A detailed description of the type of customer who gets the most value from your product and provides the most value to your business.
Lookalike Audience: An audience automatically created by platforms to find new users similar to an existing customer list or seed audience.
Custom Audience: An audience built from your own data — email lists, website visitors, app users — uploaded to an advertising platform.
Retargeting / Remarketing: Showing ads to users who have previously interacted with your brand.
Exclusion Audience: A group specifically excluded from seeing your ads — typically existing customers excluded from acquisition campaigns.
Technical Advertising Terms
Pixel: A snippet of code placed on your website that tracks user actions and sends data back to an advertising platform.
UTM Parameters: Tags added to URLs that track the source, medium, campaign, and other attributes of traffic in analytics tools.
Attribution Window: The time period in which a conversion is credited to an ad. A 7-day click / 1-day view window credits conversions that happened within 7 days of clicking or 1 day of viewing an ad.
View-Through Conversion: A conversion credited to an ad that was seen but not clicked. Important for measuring the impact of display and video advertising.
Frequency: The average number of times each unique user has seen your ad. High frequency indicates potential ad fatigue.
Campaign Structure Terms
Campaign: The top level of advertising account structure. Sets the overall objective, budget type, and major targeting parameters.
Ad Set / Ad Group: The middle level. Contains targeting specifications, bidding strategy, and schedule. One campaign can contain multiple ad sets.
Ad / Creative: The individual advertisement. The specific text, image, or video that users see. One ad set can contain multiple ads.
A/B Test: A controlled experiment comparing two or more versions of a variable to determine which performs better.
Flight: A defined period during which an ad campaign runs — often used in managed service and display advertising contexts.