The short answer
To write a good email to a website visitor, lead with relevance, not the fact that you tracked them. Reference what they care about, based on the pages they read, keep it short, and ask one easy question. The goal is a warm, human nudge to someone who showed interest, not a creepy "I saw you on our site" opener.
Start from what the visit tells you
Start from what the visit tells you. Someone who read your pricing page has a different concern from someone who read a how-to guide. Speak to that, lightly.
Do not open by announcing you identified them. It puts people on edge and adds nothing. Just be relevant, the way a sharp salesperson who noticed interest would be.
Keep it to a few short lines. One clear, low-pressure question at the end. No pitch dump.
The honest catch: a visit is a signal, not permission to spam. Reach out to genuinely interested accounts with something useful, and the warm context does the work quietly. For where the line sits, see whether visitor identification is legal under GDPR and UK GDPR.
Frequently asked questions
Should I tell a visitor I saw them on my site?
No. It reads as creepy and adds nothing. Use the context to be relevant, without announcing the tracking.
What makes a good email to a website visitor?
Relevance to what they read, brevity, and one easy question. A warm nudge, not a pitch.
Is contacting a website visitor allowed?
For B2B company-level outreach, generally yes with a lawful basis and easy opt-out. A visit is a signal, not consent to spam.
Reach out to interested accounts with relevance, while the interest is still warm.