Email Marketing
Personalization in Email: Beyond “Hi {FirstName}”

The best evidence for personalization is not a survey about what customers say they want. It is the gap between what a triggered message earns and what a broadcast earns from the same list. Klaviyo’s benchmark study of more than 143,000 abandoned cart flows found an average of $3.65 in revenue per recipient, with the top decile at $28.89. No merge tag produces that. Timing and context do.
The name is not the personalization
A first name in a subject line is a formatting choice. It carries no information the recipient did not already have, it is trivially copied by every competitor and every phishing attempt, and when the merge fails it prints "Hi {FirstName}" and tells the reader exactly how automated the relationship is. The reason it persists is that it is the only kind of personalization that requires no thought about what to send.
What actually changes behaviour is a message whose existence is justified by something the recipient did. The abandoned cart email works not because it says "Hi Sarah" but because it arrives while the intention is still live and references the specific thing that was left behind. Strip the name out entirely and the performance barely moves. Strip the context out and it collapses.
A ladder you can actually climb
| Level | What it needs | Realistic effect |
|---|---|---|
| Merge fields | A name field, populated and validated | Negligible, and negative when the merge breaks |
| Lifecycle segmentation | Signup date, purchase count | Meaningful. A first-week subscriber and a three-year customer should not get the same email |
| Behavioural triggers | Event tracking from your site or store | Large. This is where the revenue-per-recipient gap lives |
| Dynamic content blocks | A rules engine plus enough catalogue or content to vary | Moderate, and it compounds with the level above rather than replacing it |
| Predictive scoring | Volume most small lists do not have | Unproven at small scale. Skip until the levels above are exhausted |
Effect sizes are directional. The abandoned cart figures cited come from Klaviyo’s 2024 benchmark report covering flows sent in 2023.
Note the order. Most businesses attempt dynamic product recommendation blocks before they have built a single behavioural trigger, because recommendations feel more sophisticated. They are not. A recommendation block inside a broadcast that goes to everyone on a Tuesday is a broadcast with variable images. A plain-text email triggered by a specific action is personalization.
Use the data you already have, which is more than you think
Before buying anything, inventory what your existing tools already record: signup source and date, which form or landing page converted them, purchase history and order value, category or product pages viewed, which past emails were clicked, and support tickets raised. Signup source alone is underused and powerful. Someone who joined from a pricing page and someone who joined from a blog post about a beginner topic want visibly different things.
One caveat on the engagement data specifically: build your rules on clicks, site visits, and purchases rather than opens. Apple Mail Privacy Protection prefetches tracking pixels for a large share of recipients, so "opened but did not click" is not a meaningful state to personalize against. See How to Measure Email Marketing ROI for the detail.
Lawful basis is part of the design, not a footnote
If you are profiling EU subscribers to decide what to send them, GDPR Article 6 requires a lawful basis for that processing, and whichever basis you choose has to be documented and disclosed in your privacy notice before you rely on it. If you rely on consent, Article 7 requires that you be able to demonstrate it and that withdrawal is as easy as giving it. This is not merely a legal chore: a preference centre that lets someone opt out of behavioural targeting while staying subscribed is both the compliance mechanism and the retention mechanism.
Where personalization stops paying
Every conditional block you add is a template variant that has to be QA tested, and the number of paths grows multiplicatively. A four-condition email has sixteen possible renderings, and one of them contains an empty div that ships to a customer. The practical ceiling for a small team is a handful of triggers, each with a small number of variants, all of which someone actually previews before send. Beyond that point the maintenance cost eats the lift, and unlike the lift, the maintenance cost is certain.
Key takeaways
- ✓Behavioural triggers, not merge fields, produce the revenue gap. Klaviyo measured $3.65 average revenue per recipient on abandoned cart flows.
- ✓Climb the ladder in order: lifecycle segmentation and triggers before dynamic content blocks and predictive scoring.
- ✓Signup source is the most underused field you already have, and it predicts intent better than a name field.
- ✓Build rules on clicks and purchases, not opens, which Apple Mail prefetching has made unreliable.
- ✓Every conditional block multiplies the renderings you must QA. The ceiling is set by what you can actually preview.
Related reading
Sources
- Abandoned Cart Benchmark Report, Klaviyo (2024)
- Article 6 GDPR: Lawfulness of processing, GDPR text
- Article 7 GDPR: Conditions for consent, GDPR text
- Email Client Market Share, Litmus

Valter Brandt
Chief Marketing Officer
Valter Brandt is the Chief Marketing Officer of ThisCom, working with clients across the United States and Europe. He has led marketing strategy through the major shifts in social advertising, mobile, content marketing, programmatic media, and marketing automation.
All articles by Valter Brandt →Frequently asked questions
What is email personalization?+
It is choosing what to send, and when, based on what a specific person did rather than sending everyone the same message. The name in the greeting is the least consequential form of it. The consequential form is a message triggered by an action, which is why triggered flows earn several dollars per recipient where broadcasts earn cents.
Do I need a lot of data to personalize emails?+
No, and most businesses have not used what they already store. Signup source, signup date, purchase count, order value, and which links a person has clicked are usually all sitting in your existing platform. Signup source alone distinguishes someone who arrived from a pricing page from someone who arrived from a beginner guide, which is more predictive than any name field.
What is dynamic content in email?+
It is conditional blocks inside one template that render differently per recipient based on their data. It is genuinely useful, but it sits above behavioural triggers on the priority list, not below them: a recommendation block inside a Tuesday broadcast is still a broadcast. Remember that each condition multiplies the number of renderings you have to preview before send.
Can personalization feel intrusive?+
Yes, and the trigger is not the data you hold but the demonstration of how much of it you hold. Referencing a product someone looked at reads as helpful; itemising how many times and on which days reads as surveillance. If you process EU subscribers’ behaviour to target them, GDPR Article 6 also requires a documented lawful basis disclosed before you rely on it.
Related articles
Email Marketing for Small Business: The Complete 2026 Guide
The famous $36-per-$1 return is a self-reported survey figure, not a promise. Here is how a small business actually builds an email program that reaches the inbox and drives revenue, from list to automation to metrics.
Read →Email MarketingHow to Build an Email List From Scratch (Without Buying One)
A permission-based email list is your most valuable marketing asset. Here are the lead magnets, opt-in forms, and tactics that grow it ethically and fast.
Read →Email AutomationWelcome Email Sequences That Convert New Subscribers
The welcome sequence is the highest-engagement email you will ever send. Here is a proven structure to turn new subscribers into customers automatically.
Read →Related reading
- Email Automation
Email Automation 101: Workflows Every Small Business Should Set Up
Automated email flows run 24/7 and drive a large share of email revenue. Here are the core workflows every small business should set up first.
- Email Automation
Abandoned Cart Emails: Recover Lost Revenue on Autopilot
Most online carts are abandoned before checkout. A well-built abandoned-cart flow recovers a meaningful share of that revenue automatically.
- Email Marketing
Email Segmentation: Send the Right Message to the Right People
Blasting the same email to everyone is the fastest way to train your list to ignore you. Segmentation lifts engagement and revenue dramatically.
- Email Marketing
Writing Email Subject Lines That Get Opened (With Examples)
The subject line decides whether your email is read or ignored. Here are the principles and proven formulas that lift open rates, plus what to avoid.
- Deliverability
Email Deliverability: How to Stay Out of the Spam Folder
The best email in the world is worthless in the spam folder. Deliverability is infrastructure, here is how small businesses earn and protect inbox placement.