Traffic between two sites located within a few miles of each other may travel thousands of miles and pass through dozens of intermediate computers. Many ISP's offer a free trial period that can be used to test connectivity delays. National ISPs allow you to connect to them with local telephone calls from many different areas of the country. Usually there is no additional charge for this kind of service. If you plan to use it, check to make sure.
Special software used by some ISPs can be problematic.
ISP setups may replace your current browser with an older version or make system changes that interfere with other software installed on your computer. Think twice before selecting an ISP that requires you to install special software. This may not be possible with all ISPs. Think carefully about how you publicize e-mail addresses. You may not want to publicize an e-mail address you expect to abandon soon.