Possible Duplicate: Is it worth using a press release distribution service?
From either an SEO standpoint, or an exposure/PR standpoint, are press release distribution sites such as PRWeb or MarketWire worth the cost? E.g. PRWeb starts at $80/release.
Not really worth it. 99,9% of press releases are spam. Rather find a blogger, newsletter publisher or similar person who already has the attention and respect of of the market you want to reach, and then do a guest post for them, write a helpful article for their publication, etc. But remember to deliver value first, not just talk about how something you have is really awesome and how everyone should get it
Well worth the money for important press releases. You will not get picked by industry journals through these but get some online exposure. Bloggers in your field may still be your best bet and always send a copy of regular press release to all editors of relevant paper and online mags.