I wouldn't abandon traditional marketing just yet. There are some very good reasons to continue using the methods of reaching customers that you have always used. But in today's business climate, you must use some wisdom in determining which mix of traditional marketing tactics and Internet marketing tactics for your overall marketing strategy.
Yellow Pages - I'd say they're out. People use their cell phones and online sources to find phone numbers and addresses these days. Even in Adams County, Pa.
How about brochures and business cards? If you meet people face to face, then I'd say these are still useful.
Traditional marketing has not gone by the wayside. Just because you are now using a website doesn't mean that you should abandon every form of traditional marketing you have used. Radio and TV still have their places. In fact, if you have a traditional marketing method that is still effective for your business, then you should use it. But don't be afraid to replace the older methods that no longer work with more viable online strategies.