I've used
PRLOG for press releases for one of my clients. By creating online press releases you are creating more online content about your business (or your client's business), making it easier for search engines to find you. You can link to the press releases on your website, doubling the impact of the press releases (plus it looks really impressive to have press releases about your company on your website). I'm over simplifying the use of press releases, but I hope you get the idea.