At The Corner of Trademarks and Confusion, by Martha Engel, DuetsBlog

http://www.duetsblog.com/2015/07/articles/trademarks/at-the-corner-of-trademarks-and-confusion/

Even in the age of the Internet, the geographic use of a trademark is an important consideration in determining whether your mark is likely to confuse consumers as to the source of your goods or services. . . .