Get those free linkbacks! Press releases are a cheap and easy way to get public awareness of your site and promotions. Not all of them charge to send out your PR, although most have some sort of limitation to them unless you pay up (like active links in the article).
The SearchWrite newsletter had a nice list of free Press Release distribution sites. I added a few of my own to the list where you can submit articles and PRs for free.
PR Free [http://www.prfree.com/]
Press Zoom [http://presszoom.com/]
Press Base [http://www.press-base.com/]
Express Press Release Distribution [http://express-press-release.com/]
Press World [http://www.press-world.com/]
Open PR [http://openpr.com/]
Free Press Release [http://www.free-press-release.com/]
Free News Release [http://www.free-news-release.com/]
I Newswire [http://i-newswire.com/]
Newswire Today [http://www.newswiretoday.com/]
Ezine Articles [http://www.ezinearticles.com/]
GO Articles [http://www.goarticles.com/]