Ok I'm going to be critical here so be warned! Most of my comments would be techincial things so I'll start with the design. I just dont like the colours - its a personal thing I guess. Something about the light green and light blue I think. Also the site is very busy - I'm guessing ads are where the money is coming from, but they're very in your face and also they advertise mostly competing services.

On the tech side - we have the standard args:
tables rather than divs
validation
on page JS and large IDs on each element (is this due to using .Net?)
you could do more on the SEO side of things too

Sorry
des

PS liked the navigation though!