Professional services guru David Maister has a provocative post here regarding the value of talking to journalists (admittedly in the context of professional services firms).
He says: "Experience has taught me that being quoted like this doesn’t really help promote my business or affect the likelihood of me getting hired....I think the marketing benefits of talking to journalists, and press coverage in general, are way over-rated for professional businesses."
On one level, he has a point. An isolated quote probably isn't going to result in a boat load of sales enquiries. But generating many of these over time absolutely goes towards building credibility with key audiences. Also, it doesn't take into account how that quote can be used in other marketing activity - even if prospects and customers don't see the original article, nothing to stop you using links to these articles on our own website, DM, advertising, etc. David seems to have fallen into the trap of considering PR in isolation. Although one quote in itself may not be do the trick, how you maximise its usage certainly can.