tl;dr: The US dominates global self-storage with ~90% of capacity, and there are more facilities domestically than Starbucks, McDonald's, Walmart, Home Depot, Domino's, Dunkin', and Costco combined, generating over $40 billion annually. The industry, which took off in the 1970s and evolved into an institutional asset class, is driven by "the four D's": death, displacement, divorce, and downsizing. Texas leads all states in facility count, while Wichita was once dubbed the Self-Storage Capital of the US.