You folks who go through only one small jar of mayonaise in a year amaze me. DH and I (mostly DH --) go through a large jar from Costco every two months or so. I buy four jars at a time, when it’s on sale at Costco, and have gotten some strange looks. Hellmans only, of course.
And as far as ketchup is concerned, ditto. I use ketchup in many recipes – brisket, sweet and sour chicken – and we go through about three of the large Costco-sized bottles every year. Heinz only, of course.
[Quick brisket recipe: One can cranberry sauce, one cup ketchup, one packet Lipton onion soup mix. Whisk together, pour over brisket. Cover tightly with foil. Cook at 325 for three hours or so.]