If we're interested in the viability of retail across nations, revenue/sqft & cost/sqft seem the two most relevant metrics. I.e. How affordable is a business' r

If we're interested in the viability of retail across nations, revenue/sqft & cost/sqft seem the two most relevant metrics. I.e. How affordable is a business' retail space? This would have the side effect of including varying levels of foot traffic (in revenue) and real estate price (in cost), which seem the two biggest differentiators.