The darker the blue the higher the fraction of foreign Facebook connections with the imperial power in question. (Facebook has not shared the underlying percentagedata, just the ranking.) These closely correspond to countries or territories which were, whether wholly or in part, at one point under British, French, Spanish or Portuguese rule, as seen in the bottom set of maps.
In a high percentage of data centers today, these racks would be populated with servers one or two generations old, depending on corporate refresh cycles, and the average server would be a standard 2u height.
Turns out even if you sort the data by percentage of total revenue the same holds true, with only Mississippi State moving into the list in place of fellow SEC program Auburn.