Apostrophes or is it apostrophe's?

[Irulan]

You guys might find this funny.

At Target, at the pharmacists' counter, they have a little pamphlet:

Where's it at? Here's a map!

"Where's it at?" Really, Target? Your editing staff didn't catch that? It MIGHT be acceptable if "at" rhymed with "map." But it doesn't. It makes me cringe so badly that I may email corporate to ask what on earth they were thinking.

Um, Isn't "where's" a contraction of "where is"? I thought we used an apostrophe in a contraction. /confused.