The concept of a destination club was introduced in 1998, when Rob McGrath, a veteran of the luxury timeshare development business, launched Private Retreats. Since then, more than 30 companies have launched clubs targeting affluent families that want the benefits of second home ownership, but with more flexibility and choice in where they vacation each year. Inspirato with American Express is the world's largest destination club.By joining a destination club, a member gains access to a collection of vacation homes in various locations around the world in exchange for a one-time membership fee and annual membership dues. Consistent with other vacation options, inventory can be booked based on availability. Some clubs allow members to purchase different membership-types which offer different levels of reservation priority, personalized services and resort amenities such as beach clubs, luxury spas and private chefs.