It is a moment in history. The Golden Arches are now outnumbered by the Subway chain. McDonald's still serves more meals and makes more money. But in terms of outlets, the sandwich and sauce formula has conquered that of burger and fries.
It would be gratifying to think that this had something to do with all the health messages flying around the ether above the industrialised world, but Subway's secret may have more to do with its convenient locations. The bigger test for Subway, though, will be whether it can take over from McDonald's as the favourite benchmark for development. The Economist uses a "Big Mac Index" to measure the purchasing power of different national currencies. And before a couple of unfortunate recent conflicts, experts invoked the Golden Arches theory of conflict, according to which no two countries with McDonald's branches would wage war.
Subway will know that it has won when we begin talking of a "Meatball Marinara Index" and the "footlong sandwich" theory of conflict prevention.