I first saw the combination as a candy bar by Vosges. It's called Mo's Bacon Bar. I couldn't resist trying it because it sounded so weird! It was actually pretty good. The saltiness of the bacon enhanced the sweetness of the chocolate.
Then I found a local chocolate shop that made its own, getting the bacon really crispy and coating in a rich dark chocolate. Wow, that was good!
And then there were vendors at the Wisconsin State Fair selling it this summer. It made a lot of news reports locally. I didn't make it to the fair, so I'm not sure about the taste or quality there.