I read the other responses and agree with most. If you decide to go and are NOT interested in buying the timeshare or travel club, BE SURE you stick to your guns in saying "no" to all the different people they may send in to try to get you to commit. If by chance you are interested in a timeshare, look around on Craig's list, eBay, newspaper, etc. to see what they are going for on the secondary market before you go to the presentation. And if you decide to buy on secondary market, be sure to check that the owner is current with the maintenance fees due yearly. Depending on the size of the unit and location, these range from $400 to $1000+ yearly. It is not exactly a cheap way to travel, but for some people it works well and you have a condo with kitchen, etc. instead of a hotel room.
As for the freebie, it is legit, but as someone said, you pay a price in your time and patience. Plus, they sometimes black out certain dates or seasons for the trip. And, for cruises, there usually are port charges. Check on all that and if it fits for you, have fun. If not, stay away.