What worked great for me is to watch what competitors are building and to reach out where I could to get a review myself. So focus on building a great product and ask people to review it.

god business development trumps link building every time. focus on getting links from places that will send you qualified traffic (leads), and ignore your competitor until you're doing that better than anyone else.

I'm sure you've heard it time and time again, but I have to say it again - producing noteworthy and share-able content.

For example, a startup I advise called Grovo created a History of the Internet on their Facebook page. From this search (https://www.google.com/search?num=100&pws=0&q=grovo+history+of+the+internet) you can see all the press, mentions, and links that they got, not to mention shares and signups.

Start with your customers. Who are you trying to get to link to you? What are they sharing online? What content do you have, or can you produce, to get them to share it and link to it? Are you building personal relationships with these people so you can ping them when it's live? If not, you should be.

Also, egobait works great for startups. People love to be interviewed and talked about. Don't do just another Top 10 People in X Industry post. Instead, interview some movers and shakers, publish the interview, and let them know.

I'm happy to chat more about this if you're interested!

There are many ways, but I have not found a single strategy that replaces creating linkworthy content and distributing via aggressive outreach.

Here is a list of all the strategies out there...
http://pointblankseo.com/link-building-strategies

In your shoes, I would stick to blogs and websites that cover startups, and focus on generating referral traffic, not links for SEO.