Remember SEO principles apply to Press Releases too plus you have the added advantage some increased PR and legitimate link reputation.
Make sure and use your important keywords in your link text because when a press release is picked up by multiple publishers or media outlets, remember that it is news.
Many people forget that news is 100% legitimate white hat, because the search engines understand “news” is meant to be syndicated. The additional link reputation can be beneficial if your press release is carried in huge publications like Forbes or perhaps AOL Money & Finance.
Your goal with media releases is not JUST link reputation though. You also need to write a newsworthy story that will be picked up by major publications. If you don’t get your story picked up, you will missing on some huge natural traffic spikes.