If you're searching for information on a research subject who lived in a city, the method of your search is pretty straight forward. But what if the person you're researching lived in the suburbs? Turns out that directory searches are just another area in which your greater geographical understanding of the area in which you're researching really makes a difference.
The key to directory research, in this latter case, is to pinpoint the city nearest to which your target resided. Even in the 1800s, suburban areas were often included in directories for larger cities.
Case in point, consider the following 1884 directory, which is ostensibly for the city of Scranton, PA:
As the title page states, this isn't just a directory of Scranton; the volume also includes business listings for six neighboring communities.
Another example can be found in the following "Blue Book" for San Francisco (1919):
Note that the book covers not only San Francisco proper, but a whole host of suburban towns from the Greater San Francisco Bay Area.
Because it's cumbersome to list every single covered jurisdiction within the book titles on GooBooGenI, a title search for a specific suburb won't necessarily return these titles. A full search on this site would begin with the name of the local jurisdiction in which you're researching, then would slowly expand out to nearby cities, and even the county level.