It's an outdated business model fundamentally designed around publicly traded companies. For them, issuing releases on "the wire" is a requirement as a means of distributing news.
For a startup, I cannot recommend enough against a wire issuance, unless you are specifically in the financial community (or some other specific niche that I'm not thinking of). You can still "issue" a press release simply by putting it on your blog, emailing it to the press, etc. When I was running my marketing firm (www.stagetwo.com), we probably issued 100+ releases, with less than 5 hitting a wire service.