Originally published on meridianbuild.dev , my build log for OutfitMaker , an AI outfit planner that works from the clothes you already own.

On October 30 I set up the Black Friday offer for OutfitMaker : Premium annual for 39 € / $39 / £35 for the first year, instead of 59.99 / 59.99 / 49.99. It runs from November 25 to November 30, with two emails, a banner and a one-click checkout link.

Before writing any copy, I ran the email audience as a dry run. Not "send to myself". I asked the code: for every user who would receive this email, which price would they see and which currency would Stripe charge?

The answer was that 3,334 of the 3,691 accounts would be priced in euros. Most of my users are in the US.

Where the euros came from

OutfitMaker sells in EUR, USD and GBP. On the website, the currency comes from the request: the visitor's location and language. That part was fine and had been fine since early October.

Outside a web request, there's no visitor.…