Quote:
Originally Posted by
K_Thompson 
I don't even remember this playing at the theater.

Must not have been marketed very well.
It was marketed fairly well, but it was right in the middle of the holiday movie season. Its merchandising wasn't nearly as heavy as Tron or Little Fockers.
Disney dropped the franchise, because it "cost too much". Prince Caspian cost about $225m, and made a little over $400m worldwide. However, Fox only spent $155m on Dawn Treader, and has made about $375m so far. As the other posters said, they've already greenlighted the next film, "The Silver Chair", mainly because of the worldwide box office receipts.
FWIW, I saw Dawn Treader in the theater and liked it quite a bit.