Would it be really cynical of me to think that maybe they want to be able to match emails/complaints that they get to the names and addresses of season ticket holders?
If you don't give them it or opt out of receiving marketing e-mails then they can't send you them. Sorry it's a pet hate of mine. I'm responsible for e-marketing at work, people have to physically sign up to receive e-mails from us, we send them, they report them as spam. There's a simple way of avoiding receiving e-mails you don't want, don't sign up for them. Although if BFC send e-mails saying that they are "relative to leader of interior minister tragic killed in helicopter crash" and would like to give you "trusted friend" a sum of US 10,000,000$ - that's spam.