Press Releases can be effective or they can be a total waste of money. Press releases are a tool to help you gain public exposure. The benefit you get out of them can vary and is very much dependant on what techniques you use.
I have personally read countless stories of companies seeing a dramatic increase in business after submitting a couple of press releases. But I have also heard a lot about people who have never benefited from this practise.
Here are some pointers to ensure that you get the maximum ROI when using press releases:
1. Do not submit press releases for websites which are typical clones of other websites out there: PR help you best when you have something unique to offer. So if you have an affiliate website and you send out a press release, you are wasting money (most of the times)
2. Make sure your website looks professional: If you send out a PR to a website which has a crappy and uninviting design, it will not matter if people visitor your website. The traffic simply will not convert.
3. Only send out a PR if you have something news-worthy to say: This is a point which a lot of people do not understand. If you do not have anything news-worthy, do not waste your money. If however, you have started a new legitimate company, or launched a new product, press releases are a way to go!
4. Differentiate yourself from others: Who will care if you send out a PR saying that you are selling the same stuff everyone else is? Make sure that you have a differentiated product which gives people more reason to visit your website and buy from you.
5. Do something original: This is by far the most important point with online marketing. Do something original. Make sure you offer something unique. It will help you in the long run. Sure, there are many successful websites out there which are mere copies of other websites. But the amount of work those clone websites put in to get business is ridiculous. Do not fall into that trap!
One of the best press release websites out there is PR web. You can get a lot of exposure using their services if your PR is good enough.