Google sent a shockwave through the PR industry with a link scheme update that enforced new guidelines within press releases.
This article contains some good points on the effectiveness of press release distribution for SEO. The key take-away from this is that companies should write good quality, newsworthy releases intended to be useful and interesting to journalists and their readers.
It is no longer useful and can be damaging to write a press release purely to add anchor text links for SEO benefit. Google changed the rules and sees content from PR newswires as paid media, which provides no bearing on search engine ranking.
However, press releases used effectively can still benefit your business in search engine results. Of course most newswires will push your release to Google news and other news channels. This may help you get you found in the search results for some certain search terms related to your release, increasing your brand awareness and driving traffic to your website.
But the true SEO value of a press release comes when your press release is picked up by online media and published, re-used, shared and liked. If your press release is of value and genuinely newsworthy, you will inevitably get a mention and potentially a link back to your website from a reputable and authoritative website or publisher.
The final word is that online PR has changed and you now have to work harder on quality to earn your search engine ranking this way.
See original article on www.pressat.co.uk