You're doing it wrong. Please don't take that first sentence the wrong way. Allow me to elaborate and I hope this helps.
1. Press helps but they are usually "nice to have" but whatever if you don't have them. Unless you're a well funded company doing something with a lot of famous names behind your product, generally speaking, getting techcrunched, etc... brings a singular traffic spike to your site and many may not even convert. Although this is not true in all cases, long story short, don't place bets on press. They're nice if you got them but place your bets in better medians.
2. Be creative in how you aim to market your startup. For us, we didn't even get techcrunched until the day we were acquired and we never got coverage on any of the other press sites you listed. That didn't change anything. I believe Alexis Ohanian (founder of Reddit, Breadpig, and Hipmunk) said something similar. Their entire marketing budget they ever spent was a whooping $500 on stickers of the Reddit alien that they use to spread all over town.
In our case, we were in a very niche market so we spent $400 asking for a legitimate paid review (with full disclosure and allowing the reviewer to bash us for any and all negative points if there were some) from a top blogger in our niche to reach relevant audience (was well spent) and aside from that, paying for tables and booths twice a year at a targeted conference to exhibit for our product (also well spent). Some of these things are not as expensive as they seem. That said, MAJORITY of our users and marketing channels were 100% free, especially in the early stages. We focused heavily on getting the community to help spread the world. Word of mouth is often beaten to a pulp and taken out of context. The best thing you could do is get connected to all your users and do a great job for them and let those with social influence do their thing. Find out who the top influencers are in your industry and reach out, you'll be surprise how many of them are willing to give feedback and even spread the word to their friends. Its the best way to get going in the early days.
3. The earlier you are in your startup, the less you should try to blow up in explosive growth. Getting attention can also have major negative consquences too. See Color. Being a startup means you have the opportunity to roll out your product slowly and test and improve constantly before it reaches the masses. Sometimes its worth getting that explosive growth a year later, etc... Just something to think about. Right now, if I were you, I would focus 100% on the community, forget the fancy marketing tactics or press. They're not what makes your business.
