It got the email saying the 75 gallon also but when I check the store's local ad, the 55gallon is the largest listed for this sale in the local ad. Like the email ad says " Available in Select stores and While supplies last.
I'm guessing this is a good old bait and switch type ad. They will have very, very low amount of 75 gallon tanks if any at most stores.
They really don't make much offering these and people who only buy the tanks. Where they make the money is selling all the accessories such as filters, lights, substrates etc.
The sale started September 25th and ends November 5th.