If you search for a particular city location e.g. = service + city, each different city will have it's own home page referencing only that city for that service. They must do a "find and replace" for each city as the copy remains the same.
Once you are on the site and click another tab - when you click the Home tab you are taken to a generic main page - not the targeted city page that you first came through too.
They have different home pages with targeted meta descriptions that show up in google searches for each city they service. The desciptions usually say, "Are you looking for plumbers in "city"?" The title tags are geared for that city also. So you are taken to a home page that is specifically targeted for that city only. They must have over 20 additional home pages that all end in .html besides the main generic home page that's probably geared to only a few local cities and the counties.
How are they doing this? Their site always shows up on the first page for the cities they have done this for. Are they creating these different home pages and just not adding them to the menu? Why do the url's end in html though as if they are in a folder somewhere?