Google, Bing, Yahoo, Dexknows, etc. these books are now obsolete. My cell phone has the power of the search engines behind it and can show me a detailed map to any store I want to patronize. If I get lost on the way or my GPS sends me to the wrong location I can just click on this business name on my phone and talk to them directly.
So, if you are in a business that is only focusing advertising dollars in a phone book you will be invisible in this new generation. If you want to be seen you must have a web presence and if I look for you on a search engine it is your company's best interest to come out near the top. Don't let your business go the way of the the phone books, mullets, and 8 tracks. Be sure that you exist where it counts on the web!