I have really taken advantage of the free tours. It is amazing what a difference it is for three days in St Petersburg with eight tours over three days and only paying for one that included a private reception at Catherine's Palace and then a wonderful dinner.
We took the twelve person Ephesus with an Expert for free (now they charge a little extra for this tour). When all day tours include a meal you are saving at least $100 per day per person.
For our cruise next month, parasailing in Key West is free as well as all of my tours to see ruins (if I wanted the ones with flights or helos I would have had to pay more) and Arlene's snorkeling excursions.