Isn't the self-titled album the breakthrough album? I'm from DC so maybe I'm biased, but GC got a lot of airplay in our area (perhaps because GC came from MD though). "Little Things" and other singles got some airplay. I agree though that The Young and the Hopeless brought the group's mainstream, top 40 success.
I think you answered your own question. "Little Things" go SOME airplay, sure. Nothing on the S/T came close to the success of their The Young & The Hopeless