Our timeshare offered us a 4 day Carnival cruise "FREE" (and I use that term lightly) sailing out of Tampa, Port Canaveral, Mobile, Galveston or New Orleans and you pay the "port charges" of minumum $150 per person. There are different times that you can't cruise but you don't find out until you pay. You get a 1A cat. which is two bunk beds.
I am really thinking this probably isn't a good deal since you really don't know what you are getting until you pay. Has anybody else ever done a "free" cruise?
I would avoid the "surprise prize inside" approach.
All I ask is a tall ship and a star to steer her by; John Masefield
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014, Regal 2014, 2016
Sail Windjammer: Mandalay 2017
Star Clippers: Royal Clipper 2015