Check out some of their prices..and the crazy prices are usually in their flyer: https://www.aldi.us/
Apparently, it's a German chain. (I'm sure to score brownie points with mlin32 for shopping there!)
Aldi has been around for awhile in the US, but recently has been on a growth spurt. There's a few in Michigan, I recall, although not all of them are in savoury neighbourhoods. We have many in the Eastern US- 3x in Asheville alone.
Even Lidl has now moved into the eastern US; I've been to a couple of their stores in other cities.
They've adapted to North American tastes though. I find it odd that they're accepting credit cards and moving upmarket, straying away from their original "roots" in low-cost, high quality groceries. But hey, still cheaper than everyone else.
My consistent favourite market in Canada is still Metro though (Québec), a nice middle market sorta place that has some decent stuff. For nicer items, we like the IGA.