What is the click heat map?
What is the click heat map?
How to find and interpret the click heat map for a sent letter, and what it can and can't tell you.
The click heat map gives you a visual, top-to-bottom view of where readers clicked in a letter after it sent. Instead of scanning a list of link URLs, you see your letter overlaid with color: the links that pulled the most attention light up, so you can tell at a glance which stories, buttons, and ads actually earned a tap.
Where to find it
Open the letter from your Letters list, then go to its Metrics tab. Alongside the open and click totals you'll see a Heat map view that renders the sent version of the letter with each tracked link highlighted. The heat map only appears once a send has recorded click activity, so a letter that just went out may take a little while to populate as opens and clicks come in.
How to read the colors
Each clickable link is shaded by how many unique clicks it received relative to the other links in the same letter:
Warmer, more saturated shades mark the links that got the most clicks — typically your lead story, a prominent button, or the first link in a section.
Cooler, lighter shades mark links that were seen but clicked less often.
No highlight means a link recorded no clicks in the measured window.
Because the scale is relative to the letter you're viewing, the hottest link is always "hottest" within that send — it is not a fixed click count across letters. Hover or tap a highlighted link to see its exact unique-click number and its share of total clicks.
What it's good for
The heat map is most useful for spotting patterns you'd miss in a flat link report: whether readers drop off after the first few items, whether a call-to-action placed lower in the letter is being missed, or which sponsor placement is outperforming the rest. Comparing heat maps across several sends helps you decide where to position your most important links going forward.
Limitations to keep in mind
A few things the heat map does not measure:
- It reflects clicks, not reads. A link can sit in a section everyone scrolled past and still show no heat — that's not the same as the content being ignored.
- It counts unique clicks per link. If the same URL appears twice in a letter, each instance is tracked separately, which can split the heat between them.
- Clicks from readers with images or tracking disabled may not be captured, so totals can run slightly lower than actual engagement.
- The relative scale means you should compare links within a letter, not read absolute "temperature" across different sends.
- If you need exact per-link numbers — for an advertiser report, for example — use the click metrics list on the same Metrics tab rather than reading them off the heat map.