Digital Marketing Terms
Everything you need to know about email and digital marketing
Trying to decode some corporate email jargon? We got you. The Reply Two glossary spells out most digital marketing terms in language we can all understand.
A/B Testing
A/B testing (aka split testing) is when you send two versions of your newsletter to different audience segments to see which performs better. Your current best version, the "control" or "champion," competes against a new variant, the "challenger." Instead of guessing what works, you get clear data on which version wins based on opens, clicks, or conversions. Winners become your new control for future tests.
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An API (Application Programming Interface) is a set of rules that lets different software talk to each other. For newsletters, APIs let your email platform connect with other tools like your website, payment processor, or content system without manual work. This enables automatic data transfer and actions between these systems.
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An email allowlist is a pre-approved list of trusted senders that bypasses standard filtering. It ensures your emails land in subscribers' inboxes rather than spam or promotions folders. Every major email provider (Gmail, Microsoft, Apple) uses allowlists, as do most companies and ESPs.
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Alt text (alternative text) is a short written description of an image that appears when the image can't be displayed or when a screen reader is used. It tells readers what they're missing visually. Having it on all graphics and images makes your newsletter accessible to everyone.
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Analytics for email marketing is the collection, measurement, and analysis of subscriber data to understand performance and behavior. It's your newsletter's report card. It shows you what happened, helps you to discover why, and informs you about what to try next.
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Automation is the process of setting up rules that trigger specific actions in your email system without manual intervention. It's like teaching your newsletter to respond to subscriber behavior on its own, handling routine tasks while you focus on creating great content.
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Backlinks are links from other websites that point to your newsletter landing page or archive. They act as digital referrals that boost your newsletter's credibility, visibility, and search ranking. When respected sources link to you, both readers and search engines take notice.
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CAN-SPAM is the law that keeps commercial emails honest. Passed in 2003, this U.S. regulation sets rules for sending commercial messages and gives recipients the right to stop you from emailing them. Think of it as the "please behave yourself" rulebook for email marketers.
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In newsletter testing, these three terms form the foundation of structured experimentation: Control is your baseline version, the original against which you compare all changes Champion is your current best-performing version, which may be the original control or a previous winner Challengers are new variants you test against your champion. When a challenger wins, it becomes your new champion for future tests, creating a continuous improvement cycle.
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