I keep getting emails that I have 7 days left to earn from referring my friends to use Revolut. Is it really 7?

So, they appear to have a recurring campaign that invites people to their referral program every 21 days, then a reminder email on day 12 that 7 days are left. Then the amount changes (or doesn’t) and I get a new email.
The amounts vary between 50 and 200 BGN (25 to 100 Euro) with the 50 being the default, 80-90 offered when the bot felt happy, and 200 – about once or twice per year. I couldn’t find any seasonality.
These emails go back to 2022 when I probably signed up for Revolut. I’ve not yet tried the service because it wanted too much private data so I don’t know if it’s good or bad. I just admire how they never considered me an inactive user despite not having the app.

This email title only appeared once. Fellow MarTech folks on Revolut probably recognized it as something that doesn’t sit quite right.