If a company in Southern California wants to hit a target audience in the Inland Empire, they would only need to type in each city and do a search. The best advice for AOL users is to avoid public chat rooms and maintaining a user profile. You must also be aware of who you give your email address out to. Many sweepstakes are used as tools to direct email to you. The same goes towards questionares.
Mailing list are also very popular.
Make sure that the person or company that you are signing up for their mailing list has a policy about spamming. A lot of public auctions, bulletion boards, and sites that reprint visitors email will display your email address for anyone to see. If you are going to participate in these activities, use sites that offer the use of an alias instead. Your email address is not as protected as you might think. There are now many Internet white pages that collect email address and display them like a phone book.