Being listed in all directories related to your industry is a must when you launch your startup. It’s not only easy to implement but will ensure that you get an initial boost in link juice as well as some initial traffic. Find out which directories are worth your time. https://news.ycombinator.com/news
http://sus.io – list the stack you use & your app
http://firespotting.com/ – HN Clone that is mostly “Show HN” type posts
http://pitchpigeon.com/ — Paid
http://www.centercode.com/ — Paid
http://www.usertesting.com/ — Paid
http://www.prefinery.com — Paid
http://feedbackarmy.com/ — Paid
https://press.farm/ — Paid. Find journalists to write about your startup.
http://techcrunch.com/2014/07/14/please-dont-spam-us/ — TechCrunch editors email addresses.
http://startuplister.com/ — Paid. Manually submits to sites for you.