It's still fairly widespread in England, if under threat. Here is the recruiting page from one of the main companies, with over 2,500 rounds:

Advantages of being a Dairy Crest Roundsperson
# Working outdoors
# Early start, early finish
# Your customers become your friends
# Working on your own
# Setting your own goals / targets
# The more you sell, the more you earn

A lot in common with busking really...

I wonder, do we have any milkmen on the Mudcat? After all, during the hoohah about music licensing, the question of the position of whistling milkmen kept on being being brought into play.