# Tracking plan: Meridian Pro calibration mailer

This is how we know whether the mailer worked, in plain language.

## One code per recipient

Every row in `merge-sample.csv` carries a `code` (five characters, letters and digits, no zero or letter O so nobody misreads it). The code is printed twice on each piece: inside the short URL and inside the QR. The postcard and the letter for the same person use the same code, so we can see which piece a person answered from the timing, not from a different code.

## Where the QR goes

The QR and the printed link both point at `apexinstruments.example/cal-{{code}}`. That address does not show a page of its own. It is a redirect: the server writes one line to the log (code, timestamp, whether it came from the QR or was typed) and then sends the visitor on to the booking page with the code carried along in the address. The booking form stores the code with the booking. Nothing is stored about the visitor beyond what they type into the form.

## What to count

1. Pieces mailed, by piece type (postcard, letter).
2. Scans and visits per code, with the first-touch date.
3. Bookings that carry a code, and which code.
4. Bookings from the same practices that arrive without a code during the campaign window (people who called instead). The account manager tags these by hand.
5. Cost per booked calibration: print plus postage divided by bookings with a code.

## The campaign window

Count anything from the mail drop date through 45 days after the second piece lands. After that a code still works, but it is reported as "late" and not credited to the campaign.

## What good looks like

For a small partner list like this one, a response of 1 in 10 recipients scanning or visiting is strong, and 1 in 20 booking is a clear win because one calibration at partner price covers the cost of the whole mailing. Below 1 in 50 visiting means the offer or the list is wrong, not the design. Review the numbers with the account manager at day 14 and day 45.

## Sample record

| code  | first_name | practice_name              | rep_name     | first_touch | source | booked |
|-------|------------|----------------------------|--------------|-------------|--------|--------|
| HL7K2 | Priya      | Harborline Diagnostics     | Jordan Vale  | 2026-10-09  | qr     | yes    |
| CR9M4 | Marcus     | Cedar Ridge Analytical Lab | Jordan Vale  | 2026-10-11  | typed  | no     |