As has been mentioned briefly here, there are two ways to go about it:
- Go through a traditional press release service
- Build a focused list of contacts and reach out to them, or hire someone to do this
You can/should take #2 a step further and try to build more substantial relationships with press/media/influencers. You'll find much better results reaching out to people you've already been in touch with than when sending out cold press releases promoting your new launch. It helps if you initially engage them without directly asking them for anything. Twitter is a great platform for this. Follow them, fav/RT them, and when you have a meaningful comment to make, jump in and say it.
The most effective press strategy would honestly use both 1 & 2 mentioned above. Targeted outreach is great, but if you have an exciting story/launch you want to broadcast widely, a press release service can get you in front of a ton of journalists, and some even guarantee you'll appear on a certain number of sites.The best way to evaluate a press release service is by examining the network(s) they send out to. Different services will be more focused on different areas, eg web vs traditional media. More on that here: