Newsletter advertising glossary
Clear definitions for the terms publishers and advertisers encounter when monetizing newsletters — from eCPM and fill rate to open-time ad serving and SSP/DSP.
Ad Journeys
Sequential newsletter ad campaigns where subscribers advance through steps based on previous exposure.
Ad Placement
A defined slot within a newsletter where an ad is displayed to subscribers.
Ad Waterfall
A prioritized sequence of demand sources the ad server checks to fill an impression.
Apple MPP (Mail Privacy Protection)
Apple's iOS 15+ feature that pre-fetches email pixels, inflating open rate metrics.
CPC
Cost per click — an ad pricing model where the advertiser pays only when a subscriber clicks the ad.
CPM
Cost per mille — the price an advertiser pays per 1,000 ad impressions.
CTR (Click-Through Rate)
The percentage of ad impressions that result in a click.
Direct-Sold Advertising
Ad campaigns sold directly by the publisher to advertisers, without programmatic intermediaries.
DSP (Demand-Side Platform)
Technology platform that allows advertisers to buy ad inventory across multiple publishers programmatically.
eCPM
Effective cost per thousand impressions — the actual revenue earned per 1,000 ad impressions.
Email Hash (SHA-256)
A one-way cryptographic transformation of an email address used for privacy-safe ad targeting.
ESP (Email Service Provider)
A platform used to create, send, and track email campaigns and newsletters.
Fill Rate
The percentage of ad requests that result in an ad being served.
Floor CPM
The minimum price a publisher will accept for an ad impression.
Frequency Cap
A limit on how many times a specific subscriber sees a particular ad.
GDPR Compliance in Newsletter Advertising
How newsletter ad serving can satisfy EU General Data Protection Regulation requirements.
Gmail Image Proxy
Google's image caching system that serves email images through Google's servers, affecting ad decisioning.
Native Ads
Ad format that matches the visual style of editorial newsletter content.
Newsletter Ad Network
A platform that connects newsletter publishers with advertisers at scale.
Newsletter Monetization
The strategies and tools publishers use to generate revenue from their email newsletters.
Open Rate
The percentage of newsletter recipients who open a given email send.
Open-Time Ad Serving
An ad serving technique that runs the ad auction when the subscriber opens the email, not when it is sent.
OpenRTB
Open standard protocol for real-time programmatic ad auctions between buyers and sellers.
PMP (Private Marketplace)
A private, invitation-only programmatic auction between a publisher and select advertisers.
Programmatic Advertising
Automated buying and selling of ad inventory using real-time bidding technology.
Sponsorship CPM
The effective CPM of a flat-fee newsletter sponsorship deal.
SSP (Supply-Side Platform)
Technology platform that helps publishers manage and sell their ad inventory.
Ready to put these concepts to work?
MailAdx is the newsletter ad platform behind open-time serving, publisher SSP, and advertiser DSP.