"Surely it will sell like hotcakes," Jen Doll wrote today about Pippa Middleton's forthcoming book on entertaining Celebrate. The line got one commenter wondering where that common phrase came from. Guest writes

Not to quibble, but why do hotcakes sell so well? Is it because you sell them in stacks and not separately? I detest them, so I never understood where that old expression came from. Maybe hotcakes were a big trend back in the day, or is it that they can be made cheaply and so you can buy a ton of them?

Well, Guest, according to Mental Floss, no one's really sure where the saying came from: 

... this phrase, with the figurative meaning “to be in great demand,” didn’t appear until around 1840 and there’s no evidence of a great hotcake demand that might have led to its creation. Instead, etymologists are left to assume that since hotcakes have always been popular at events like county fairs and church socials, where the crowd greatly outnumbers the culinary staff and the cakes often sell as fast as they can be made, the term was coined and spread through popular usage.