There are many reasons to come to Sapa. The two main are: to see how local minorities live in Vietnam, and to go on a trekking on the mountains. People who live in the region still use their traditional clothes (young and old people alike).
They also speak their own languages -- each tribe speaks it own. The tribe people belong to a different ethnic group than the rest of the Vietnamese people. Although tourism is developing fast in the region, many locals still live a very basic life. Most of them spend all day long working on the fields.
They sell what their families do not need in one of the weekend markets. And with the money they make, they buy something else. It is what experts call a subsistence economy. No luxuries here.
Vietnam Travel - Sapa Travel Guide