They run this deal a couple times per year. Sometimes with freebies such as a take and bake pizza, paper towels, etc. We have been a member for years. Plus member. Between what we spend for crap at home and the occasional things for my wife's work it more than pays for itself. Think the plus membership is $90. We've gotten back $250+ every year in rewards for at least the past 3 years I can remember.
Also a Costco member. They roped us in with a groupon deal where it was $60 for the membership, they gave you a $40 costco gift card and a coupon for $40 off an online order over $250. Ended up getting a new fridge there, some random christmas gifts and both my son and my son in law used the membership to order Xbox's online. Couldn't find them anywhere else when they went on pre-sale.
End up going to Sam's more often because it is just a couple miles away down the street and I'm a big fan of their scan and go app. Don't ever have to go through a checkout line there.