The biggest suggestion I could offer would be to give your potential customers a reason to use it - ask them a question on the conversion page that qualifies them as a customer - i.e. "Want to spend your money more effectively?" or "Want to cut down on the amount of time you spend tracking corporate expenses?" or something similar. As is, the site kinda assumes that everyone has the problem you are trying to solve, which has the affect of making it appeal to "no one". Be more explicit about the problem you'd like to solve in your copy and it will boost user confidence immensely and get many more of them to the point where they will want to try your service.