Here in the US you'll find a vast majority of the land used for self-storage is owned by either investment firms specializing in commercial/self-storage real estate, MLP's (Master Limited Partnerships), or REIT's (Real Estate Investment Trusts). There are a lot of nuances to it, but essentially these are tax vehicles that buy up a bunch of not particularly sexy land, but in an industrious location that has long term potential. The issue then becomes what to do with the land while you sit on it, and the answer to that is self-storage. Self-storage warehouses are incredibly cheap to build and operate, often times the largest cost is insurance (although that's not saying much nowadays). Many MLP's/REIT's either own their own self-storage company, own a controlling share in one, or at least own a good percentage of one, or the self-storage company in and of itself is an investment firm wrapped in a thin veneer of self-storage. Thus, on top of the rent you can get a nice cut of the storage profits. It's a fantastic racket if you can get momentum, after a certain point the money essentially prints itself and you still have control of a massive chunk of land to boot. The self-storage business is also very predictable, and highly tuned, so the investment returns on both the land and the storage business are very conducive to long term wealth building.