Whats the best way to track success of ad campaigns?

Hey Guys, We just launched Mingle Trips and I am using various ads on Facebook to get initial users to the site. But my problem is that I do not know how many of them are actually converting - ie. creating a trip on Mingle Trips. I can create different landing page for each campaign and track that way. But this looks like too clumsy a method. Is there a better way to do this? I tried Google Analytics and KissMetrics, but doesn't solve my purpose. Thanks.