I only get the offer emails for selected venues. Ones for Birmigham come through but not for Bristol or Wimbledon. No idea why but that’s the way it is
It shouldn't be random at all as you can check via your account (which I think is possible even if you are a mailing list member only rather than a full member, but I am sure someone will correct me if I am wrong) to see which venue mailing lists you are subscribed to. It is quite hard to navigate to the right section of the website but this is how I checked and it only deepened the mystery of why my chosen venues never email me.
I need to do this as I get constant ATG offers for Oxford Theatre. I'm sure it's lovely but I've never been and am very unlikely to ever go so not sure what is going on there!