"Lent is very important ... especially after a hard winter," John Gordon, a restaurant analyst with Pacific Management Consulting Group, told Insider.
According to Gordon, attracting customers with fish during Lent can be crucial in transitioning from winter (when sales sometimes lag) into a successful spring. With customers looking for non-meat options on Friday during Lent, a fish-based menu item can provide a short-term sales boost driven by people avoiding burgers.
McDonald's Filet-O-Fish was developed to win over Catholic customers who weren't eating burgers during Lent.
Hollis Johnson
McDonald's iconic Filet-O-Fish was invented to win over Catholic customers during Lent. Back in 1962, franchisee Lou Groen was struggling to sell burgers on Fridays, as Catholics were abstaining from meat. So, he developed a fish sandwich with tartar sauce.