Mr. Boffo lays an eggcorn

Today's "Mr. Boffo" strip has a new eggcorn candidate for Chris Waigl's online collection.

The text reads: "It's all about people. Money is only a bi-product you get when you squeeze them hard enough and long enough."

I had never seen bi-product for byproduct, but it's a logical enough mistake: Here, Mr. B (as corporate executive) is interpreting by-product -- an incidental outcome of a process -- as bi-product, one of two simultaneous results. (But what is the second product he refers to -- simply sadistic pleasure?)

This by- prefix, meaning "aside, apart from the main issue," is fairly uncommon now; an illegitimate child, for instance, is no longer called a by-blow, as Fielding's Tom Jones was. But we still have byplay and bypass to remind us of why it's byproduct.

Biproduct is also a real term, says Wikipedia, but it's not exactly a household word: "In category theory and its applications to mathematics, a biproduct is a generalisation of the notion of direct sum that makes sense in any preadditive category."

All right, then. But I suspect the mathematical biproduct is too arcane to be tempting writers into careless misspellings. In Mister Boffo's use, at least, biproduct has all the marks of a genuine eggcorn.