That link just takes people to their own gmail page. It isnt going to show the offer, but it is a legit offer.
I also got the notice, that makes at least 200 communications from them in the last year,via my junk email account, or the mailbox. since my Equinox went off the 3 month free trial. It would have been many more had they been provided my actual phone info. They are desperate for customers.
If you like their service, hammer them on price, and do not pay anything close to what they want.