Idaho, What’s With The Roadside Sweet Corn?

I've seen all kinds of things being sold on the side of the road and at freeway exits:
Oranges, blankets, roses, flags, pottery, tee-shirts, water, stuffed animals, canvas paintings. I mean all of the things. And I have not once ever stopped to procure any of these items from their vendors. It just never seems worth the time and anxiety that traffic will start moving and you will be holing up the intersection because you wanted a generic teddy bear.

But for the last week, every day on my way home from work and when I run errands, I've seen this large sign for sweet corn on Ten Mile and Pine before you hit the freeway. For one, I'm not even sure what sweet corn is, let alone in the context of Idaho. And there is no pricing I saw visible on any sign, so that doesn't inspire me to stop. But I can't stop thinking about it.

A friend of mine who moved here from Indiana mentioned to me that sweet corn is to Indiana what potatoes are to Idaho...but what is sweet corn to Idaho?! I guess before I pull my car over to get myself some, I'd like to know if sweet corn being sold roadside is commonplace. Were I to drive around town would I be seeing sweet corn at multiple intersections? And is this stuff any good? A lot of food is overhyped, like the ice cream potato (don't hunt me down with a pitchfork. I'm sure tons of people love it. It's just not for me.) Also...should I try and start my own sweet corn vending situation? How's this all work?