ok, I must be friggin blind. I just found an old optimization invitation email from almost a year ago from Google Adsense I never replied to (obviously because I just found it now). I was to reply within 10 days. I just received another optimization invitation email not too long ago also, but it had a different offer. And no, I have no where near 20 million page views a month that I have been hearing about to become a Premium Publisher. Anyone ever get these emails, and if so, did your earnings increase after implementing their 'offers'? Yeah Mobius... I am 'bragging'. LOL.
I have heard first time from you, I don't think that google will send these type mail. it may be fake copy mail of adsense google.
If the message is on your Adsense account, then yes, that is real. I also got such messages on my adsense account regarding optimization of ads.
One message was through my Adsense account, and the other one from a year ago was through regular email. The year old one looks real. The reply email is Google, the email headers all say Google. They have my name, Publisher ID, etc.