Availability trumps loyalty.

From David Gottlieb on the Behind the Numbers podcast:

In our specific primary research, we find that 40% of shoppers will brand switch when they can’t find the item they’re looking for.

But if you’re buying a consumer good like a soup or a mac and cheese or a home cleaning product, people are brand loyal to a point, but if they need something for a recipe or to complete their shopping mission, they’re probably not going to go home empty-handed.

That’s a real challenge for brands because brand loyalty is built slowly over time and it can erode very quickly if somebody is forced to try a competitive product, you’re giving them an opportunity that you don’t want them to have essentially as a loyal brand shopper.