I built a small blogging engine http://substancehq.com http://substancehq.com, and have had more than 30 throwaway blogs created by "generated guest credentials

I built a small blogging engine http://substancehq.com http://substancehq.com, and have had more than 30 throwaway blogs created by "generated guest credentials" on the first day. This is a great thing for a new guy like me. However, most users don't follow through and finish the sign up, which tells me that the app itself is not appealing to the users. This approach is a lot better than having bounces off your signup form. I wonder why many people don't do this.