And what if it is a social idea whereby monetization comes only with traction? IE: Dropbox, etc, and a initial invest of time, say at least 6 months is needed t

And what if it is a social idea whereby monetization comes only with traction? IE: Dropbox, etc, and a initial invest of time, say at least 6 months is needed to the product ready, what should I do in a case like this?