The two most common ways to distribute press releases are via e-mail or fax. Unfortunately, both methods are heavily abused by spammers, who send out untargeted press releases and solicitations to journalists at a rate of hundreds per week.
The best way to ensure that a press release is actually read by a media contact is to capitalize on an existing relationship. If the journalist knows that you've spent the time to research his tastes, or has received newsworthy stories from you in the past, he's much more likely to pay attention in the future.
Still, some situations call for the ability to send many targeted press releases at once. E-mail makes this easy. Paste your press release in the body of an e-mail (some filters automatically delete messages with attachments), address it to all the journalists you want to contact and press send.
Advances in fax technology have also made it easy to "broadcast" a faxed press release to many recipients without faxing each one individually or spending the money to pay for all the long-distance phone calls. This is accomplished by desktop fax, a technology that enables users to send and receive faxes from their e-mail accounts. For a company to use desktop fax, it has either to buy special fax servers or subscribe to a third-party hosting service.
Like regular e-mail, it's possible to send desktop faxes to many recipients at once. Simply add all of the fax numbers as separate e-mail addresses.
Web-based fax broadcasting services work similar to desktop fax but with a few extra features. Using a Web interface, you can schedule press releases to release on a certain day and time and even include a preset number of redials. Web-based fax broadcasting services also allow you to upload contact lists from spreadsheets or existing e-mail groups. Some also include reporting services to see which faxes went through.
For lots more information about press releases and related topics, check out the links below.