First off let me say I write Press Releases for my clients and myself. Most of my Press Releases get on the first page of Google News. Most of them get many views. Most over 1,000 views and most get between 20-30 clicks on the website that links to them.
None of my clients that I know of have ever had any huge success with Press Releases. After doing several for myself and not getting any leads to speak of I am starting to not believe that they work or else I am writing them in the wrong way.
I do believe that they are good backlinking juice. Outside of that I am finding less and less value in them. Writing Ezine Articles seems to be just as effective, if not more effective than a Press Release that cost between $50-150.