While there is no substitute for contacting media pro's directly, submitting your release through sites like PRWeb does help gain exposure and in many cases positively impacts search marketing. If you use more than one distribution source, make sure to make modifications not only to the title (seperate titles if possible) but also to the body of the release. Always track individual releases and of course, use keywords in both title and content and use
PR as a marketing approach only when you have something truly significant to say or announce.