He hasn't really done much more than somebody like Danny Graham has done only doing it at an earlier age.
Graham scored 24 for Watford in the Champ, then in his first top flight season had 10 by about the half way mark only to tail off a bit second half of the season. Carroll scored 17 in the Champ, then had 11 top flight goals when Liverpool paid £35 million for him.
What's the difference? Carroll had some very impressive individual displays and scored some goals against the better sides in his favour, but generally the stats and upwards curve align fairly similarly.
Similar story for Andy Johnson in 04/05 and Michael Ricketts in 01/02.