Budweiser is swill that passes for beer in the USA, because it is cheaper than what most of the world recognizes as beer -- until savvy people made microbrews popular in USA, and they are not in grocery stores.
All over the world you can find people drinking similar lagers. Bubbly, mild flavor, easy to drink. They have mainstream appeal. Quilmes, Singha, Asahi, King Fisher, Labatt, Skol, Tsingtao, etc. There are too many to name. You can find at least one in every country I've been to. I would say Budweiser is one of the better examples of this style.
The Boston Beer Company (maker of Samuel Adams) is still technically a craft/micro brewery, since they produce (intentionally) less than 6 million barrels annually. The entire craft brew industry produces less than 8% of all domestic beer.
Calling Sam Adams a "major brand" is a bit of a stretch.
