If any further evidence was needed to demonstrate the rapid growth in popularity of same day delivery services it may have just been delivered by the news that USPS are expanding their services in the arena. Up until now USPS had been experimenting with what they’ve called ‘Metro Post’ in just San Francisco (which struggled) and New York City, but now they have announced that the service will be expanded to include Washington D.C. along with certain suburbs of the city in Virginia and Maryland.