I think blogs are the thing. Also find the Yahoo groups that feature your genre.
A formal press release to media is a thing of the past, especially if you're a small publisher and/or indy author.
On the other hand, I usually don't know what I'm talking about when it comes to marketing, so I'm interested in others' responses.
If you already have a well-written release, use PR.com which is free. Also, check out PRWeb. If you want a wider distribution, I can give you the name of a company I used who distributed to over 1,850 media outlets, and gave me the list to follow up on. Contact me through my "contact page" on my website if you want more info on them.
Author of Husbands May Come and Go but Friends Are Forever
I'll contact you on your site.
I find press releases useful to send to reviewers so they have a summary and all the pertinent info about a book. We've had requests to send books to Midwest Book Review on the basis of our press release.
However, I would warn about sending a release through some of the paid services because you have no real knowledge on whether or not the press release was really useful even if you try to target the appropriate market. Last year I sent a press release out on behalf of an organization. And while it got thousands of impressions, there was no real increase in responses generated from it. You have to decide what you want and what your budget you have (if any). Frankly, we've had better results/exposure by using Book2Book News, which is a popular online resource that allows you to upload press releases for free.
I advise making a list of venues that target the market you want to reach and focus on them. Try to get some high-profile/popular blogs or publications (online and/or print) and submit your news to them.
I had a similar experience using free press release companies. I got loads of impressions, but not much work from it. Though, even the few bookings I did get I would consider a success considering I only used free services.
Perspective is everything I guess.
10 Things College Students Need to Know About Money
I've spent the last couple weeks searching for a publicist. Many of them have samples of their press releases online. So you might check out what the pros are writing and use it for a template. I've gathered a couple good ideas already that I hadn't thought of.
Blogs, PrLog, members of the media, Facebook notes, Facebook invitations...