Some useful articles on this topic that may provide inspiration:

http://thenextweb.com/entrepreneur/2013/12/18/successfully-u...

http://malcolmbell.net/2014/02/28/my-mailcloud-app-10000-use...

http://www.fastcolabs.com/3024472/how-we-got-our-first-2000-...

http://popcornryan.tumblr.com/post/65640245447/how-i-got-my-...

http://www.quora.com/Marketing/What-are-key-strategies-to-ac...

http://blog.yesgraph.com/first-1000/

http://www.austenallred.com/the-hackers-guide-to-the-first-1...