Cart or horse?

A killer on-line web application that will take 2 days to build and launch.
Should you build and launch and then figure out how to make money from it or sit down and figure out the money first?

If you launch first you can let it work and build a user base and word of mouth.
However when you change it to a paid service would you risk getting the backs up of the users who would have paid for the service originally?

Could this be why some on-line services launch with “Beta” to get around this issue?

1. Yeah do the beta route, and make sure users know there may be a charge when it goes live. I have some websites planned, this is how i intend to do it.
   — Brian O'Neill    Nov 3, 10:09 AM    #