After the quick-wins with Owwly, YourStack & co, this one will be a bit more work - and ongoing. Before you hit the "delete" button, let me tell you why I think it's worth it. Like offline media, online media has its "stars". Think about large publications such as Forbes, Business Insider or TechCrunch. These websites often rank in the Top 1000 on Alexa and have millions of visitors monthly.
Being mentioned by one of these large websites can drive a substantial amount of traffic to your project. With this you have the chance to either win more paying clients or subscribers, if you are running a newsletter. The exposure also brings the chance to connect with more bloggers, etc. and attract more mentions. With each of these mentions you will potentially receive a backlink to your project - which drives up your ranking on Google and Co.
As with everything, this doesn't come for free. You can't just send an email to a reporter and ask to be featured. This will not even get you a response. You've either got to build a relationship using Twitter etc. - a long and slow process I've never managed to pull off - or you go to where reporters and writers go to find information. Let me introduce you to "HARO" (help a reporter out). It's a free platform I've been using for a while to build up attention for my projects.