See also: Micro-ISV.

https://en.wikipedia.org/wiki/Micro_ISV

http://www.amazon.com/Micro-ISV-Vision-Reality-Bob-Walsh/dp/...

http://ericsink.com/bos/Micro_ISV.html

Make sure to read this to get a different take though.

http://www.singlefounder.com/the-day-the-microisv-movement-d...

Bob Walsh/Micro-ISV from Vision to Reality (2006) - has a big chapter with interviews of starting "niche" companies from just launched to very successful(HubSpot/FogCreek). It was interesting to revisit their websites and see how many of them survived. Some are dead, some had failed products but they came up with new ones and became successful.

http://www.amazon.com/Micro-ISV-Vision-Reality-Bob-Walsh/dp/...