FWIW I've heard storage units are not necessarily a super profitable business, instead they are a low overhead operation to cover the property tax on land in the outskirts that you're sitting on waiting for appreciation as the city grows. So they only have make up the cost of the cinderblocks to be worthwhile.
I don't really believe that as in many places you're starting to see multi-level facilities with as many as 5-6 layers of units. That ain't cinderblocks.
In California at least, prop 13 lets them operate without having to worry about rising property taxes in areas where otherwise there could (and probably should) be housing.
I knew of a dude that had a couple of the storage facilities. I guess the facilities themselves had a slim profit margin, but he could auction off the contents when folks didn't pay - which partially made up for the margin. Granted, this was mid-size midwestern city, so the land cost wasn't as high.
