How do I know if a newsletter sponsorship paid off?

Before it runs

1. One link, only for this send: ?utm_source=newsletter-name&utm_medium=sponsored&utm_campaign=2026-10. Email clients often send no referring site, so without the tag these visits look direct.
2. A code, if you give a discount. Some readers type your address instead of clicking; a code they enter at checkout still says where they came from.
3. Write down what it cost and the date it goes out.
4. Check your signup keeps the source, and that payments can be matched to signups by email or user id.

What to count

• Visits on the day: tells you the newsletter reached people. Not whether it worked.
• Signups from the tag in the following weeks: tells you whether its readers wanted it.
• Paying customers and their revenue after 30 to 60 days: the only number that says whether it paid off.

Then:

• Cost per customer = what the placement cost ÷ paying customers it brought.
• Return on spend = revenue from those customers ÷ what the placement cost.

Why waiting matters

Newsletter readers read on their own schedule: the day it arrives, the weekend after, a week later from a saved email. Many visit once, leave, and sign up on a later visit, often typing your address. If you only count signups on the first visit’s day, you undercount; if your tool keeps the first visit’s source for returning visitors, those later signups still count for the newsletter.

A worked example

Say a placement costs $400 and brings 300 visits, 24 signups and, after 45 days, 4 paying customers at $25 a month. Cost per customer is $400 ÷ 4 = $100. If customers usually stay about ten months, each is worth around $250, and the sponsorship was worth repeating. If the same send brought 1,000 visits and no customers, it wasn’t, however good the day looked.

Before you book again

Ask the newsletter for its readers’ profile, and compare it with where your paying customers came from. A smaller newsletter whose readers match your customers usually beats a bigger one whose readers don’t.

With Nordva Launch

Every visit keeps its UTM tags, and in the visitor-id modes a returning visitor’s signup counts for their first visit. With Stripe connected (read-only, every plan), paying customers are traced to that first visit. On Builder, enter what the placement cost against its utm_source or utm_campaign, and Launch shows cost per customer and return on spend for that send. Channel costs start on Indie, but on Indie the report groups by referring site, which clicks from email often don’t have.