Great looking site and service. There are a few out there so the fact that your site looks great is a good starting/selling point as an initial reaction to a potential customer.

The one thing I would say to help get the sales would be to add some kind of list of what you get (an overview if you will) on the pricing/plan page. Since you have a link to the plans page right on the main page, a user may skip the area where you list what you get when you buy. So to have the list on the plans page will eliminate the chance of someone possibly leaving the purchase page to look at plans and potentially lose the sale.