A cautionary tale: I had good luck with ZoneEdit when they launched. It was/is kind of in the same space as this. Their new UI is okay, but yours looks a bit better. They started out with freemium, but eventually had to re-structure how their premium service worked, and in the process crippled how the free service worked. It got bad enough that I abandoned them.
Be very careful how you structure your premium offerings. People don't like when the free version starts losing features or capacity.
Be very careful how you structure your premium offerings. People don't like when the free version starts losing features or capacity.