I would rather use Google Analytics to do this, with a couple of good old UTM variables and a GA event on form completion.
If you are using UTMs and have setup attribution properly, you can definitely look at this. Are you driving people to the Request Form with emails? PPC? Organic?
Jamie and Greg are suggesting that if you used UTMs and/or wanted to look at other traffic sources, GA would provide more visibility. This assumes a bit that GA is also setup to handle goals or form conversions on your site.