>>jjcm+(OP)
I've spent enough time [Edit: on HN] to remember App.net¹ which was launched with similar fanfare but was shut down after few painful years of trying to find a PMF. The lesson I learned from that saga was HN might not be the best place to validate your product. We're too smart to diss even good ideas like DropBox.
Go and talk to your potential customers and I hope the App.net story gives you some inspiration.
1: >>4372985
2: >>13387723