Been a paid user since 2008 and these promo popups annoys the heck out of me as well.
I could accept it maybe once, regardless if I have opt-in to marketing or not, but how it came sooo many times was really annoying.
Yes, this might be a user-to-user forum (but I'm sure somebody at Evernote is reading here (or at least they should!), and in the old days they also replied), but even so, I think it's fine to warn potential new paying customers that even though they pay, they should be prepared for regular discount/upgrade offers during promotions...
After the first few times I started wondering if they are running out of money or something since they so aggressively push upgrades on already paying customers, and actually made me consider finding an alternative before they shut down. I hope it's just some overly ambitious marketing-person trying to make their quarterly bonus that's the reason behind the pushy promotions, and not because the company is in a bad shape financially.