WLS = World's Largest Store

But, as we are primarily ag-related people here conversing now, it's interesting to note that WLS started as an ag station. Times have changed...big time. I do remember we'd listen to the WLS Barn Dance when milking cows as a kid. For some reason, there was a big old radio in the alleyway of the barn. I remember listening when Dick Biondi (the Wild Itralian (not misspelled)) first hit town. A friend & I were building model cars in his basement listening to the "On Top of a Pizza" song Biondi came up with. I'm not real sure we knew what pizza was yet.

Here's a good history from Wikipedia:

http://en.wikipedia.org/wiki/WLS_(AM)