These free PR sites can be helpful to get releases listed in the rankings. They have mixed results in terms of generating high value backlinks. They can't hurt, but may not help:
PRlog.com (Requires uses to set up a free account, and then distribution for press releases can be done for no charge.)
Mediasyndicate.com (all releases are reviewed for content and formatting)
Paid Press Release Distribution
The advantage of paid press distribution is the quality of sites that syndicate releases. These include:
PRWeb.com - Prices range from $80 for a basic release to $360 for an AP wire release. Call and ask about annual subscription via small business Vocus program which provides substantial savings per release. Annual subscription excellent choice for most businesses looking for solid distribution.
MyPRGenie - free for one newsroom and unlimited press distribution, to $300 per month. Also owns ProfNet, which sends daily story opportunities to you by reporters ($1000 per year)
marketwire - good lower cost option (around $200) for AP distribution if you keep release to under 400 words and only include one http: link. More words, links and media quickly raises cost.
PRnewswire - $195/year membership - fee waived for first year
24-7 pressrelease - $49 per release
prleap - $49 to $149 per release
addpr.com - $25 per release
Businesswire - considered the cadillac of pr new release services, for larger more established companies. Approx $395 per release or more.
Social Media Press Release Distribution
Pitchengine.com - free for 30 days and distribution, $35 a month to keep release active. Helpful direct connections into major social media platforms.
Please provide comments on your experiences with both the free pr platforms, paid pr platforms and social media distribution platforms.