It is a hosted solution and you pay for it, for starters. Ghost will be open source, you host it.

Ghost will have a hosted platform as well [1].

  * November 2013 - Release of the hosted platform to Kickstarter backers
  * January 2014 - Release of the hosted platform to the general public

[1] - http://www.kickstarter.com/projects/johnonolan/ghost-just-a-...

Ghost is similar to wordpress. You will need to setup and maintain your own servers with Ghost.

They will be providing a hosting service later on.