this article, there are over 400 of these shops in Vietnam. High tarriffs keep Starbucks and other chains out.
Since French colonial days, coffee has been an important part of the Vietnamese economy and culture. Vietnamese coffee is a very strong espresso style beverage.
One popular method of serving coffee commonly found in Vietnamese restaurants in the United States is iced coffee with condensed milk. Condensed milk is poured into a glass of ice and then a small pot filled with coffee grounds is placed over the glass. Hot water is poured into the pot and when the coffee is finished seeping into the glass, the coffee, milk and ice are stirred.
In any third world country, tourists are warned not to drink the water. In Vietnam, we stuck to bottled water, but ice is just as dangerous.
One morning I saw a local shop preparing their ice for the day. A large block of ice had been delivered to the shop and one of the workers had set it on the dirty sidewalk and was chipping it with a rusty machete. That sight kept me from drinking any beverages that involved ice. I stuck to refrigerated cans of soda and fruit juice.