I always book using ES and from what I understand it's you responsibility to keep watch to see if prices drop. I'm pretty sure your phone will never ring with them telling you it's gone down. Also I always keep an eye on the price and I have never had the price drop on my booking.
You can shake the sand from you shoes but it will never leave your soul
Home is where you park your flip flops
Carnival - Fantasy 1998
RCCL - Majesty of the Sea 2000
Carnival - Inspiration 2009
Carnival - Freedom 2011
Carnival - Liberty 2013