The beginning is always the biggest challenge for me, you have to hussle in the short term to get things going.

You say that the service has huge value, but have you tested this with users to make sure their understanding and perceived value of your value proposition is in line with your own?

I have recently read a few books that you might find useful.

1) Ask - Ryan Levesque
2) Inbound Marketing - Brian Halligan, Dharmesh Shah

You can also find loads of information about inbound marketing online.

Good luck