- Just because some people clicked on features they want, it doesnt mean they will pay for it once you launch.

- Just because some people are using your free features, it doesnt mean they will pay for it once it is paid.

- Just because you have 5 paying customers, doesnt mean it will be easy to find out 500 more.

- Just because you have 500 paying customers, it doesnt mean what you did to acquire these 500 will scale to the next 5000.

- Just because you have 5000 paying customers, it doesnt mean that there won't be a new upstart which will dramatically undercut your offering and acquire most of these.

There is a name for this validation process - its called a 'startup'.