Vacation ownership interests: Deal or no deal?

Slew of surprises revealed in timeshare's fine print

Q: On a recent vacation to the Caribbean, we were approached by a young woman who wanted us to buy into a vacation ownership. According to this salesperson, for the money that we would give them, we would get a number of points, which could be used for vacations in a number of desirable hotels and cities throughout the United States. This was interesting to us, but we did not know enough about the transaction and opted not to buy. Can you provide some guidance on this concept? Is it a good deal?