The year is 2010. Press Releases used to be a viable option to distribute breaking news. I don't think that applies anymore. With the onset of Social Media, PR sites have become dinosaurs.
PR Websites may not be too effective, but depending on what industry you are in, PR could be a MUST. Imagine releasing a film without PR or press releases. That means without any industry or Trade press. You might think, if you want Variety to write about you, just email them directly with your release. And you can, but newswires exist to do that for you. Films with multi-million dollar budgets may be an extreme example, but it helps to illustrate the role of serious PR.
A few years back we did a press release for a game via an online service that put us on the newswire. We were contacted by the top 30 major game review sites, newspapers, magazines, airline in-flight commercial producers and others. So it can give a lot of bang for the buck.
A Press Release is just a tool in your toolkit, but it may be your most powerful tool. Having said that, if your press release does not adhere to the industry standard format you will get very little attention at all, because it will be seen as an amateur attempt at getting links or a free article. In other words, when your press release is done in the same way that the majors do it, who get written up in national press every time they do a release, then you will get some attention, if only because your presentation tells them you are somebody that bears watching.