It`s true that PR is not for every business. It`s really best for companies and owners that truly differentiate themselves in some way. (i.e. it`s about the story). So yes, I`ve been approached by businesses like dry cleaners that want to see their name in ink. The problem is that they are no different than the other 10 dry cleaners within walking distance of my house. So, they advertise and do money mailers, because without a story they will not generate "the story" in press. The variety of marketing mix elements allows for all businesses to achieve recognition and brand awareness through a diverse combination of opportunities.
However, if you have something unique that consumers, or your potential business clients will be interested in, then there is nothing more valuable than a third-party endorsement. Think of it this way, even you are more likely to try or buy something, or even go to a doctor, after a friend has recommended it highly (insert reputable journalist here). PR generates a crediblity that other marketing elements just can`t. That`s why it`s ideal to create integrated programs when possible - cover all your bases.
Hope this helps as well.