Professional travelers are similar to business travelers in many ways, although this type of travel is more elastic than business travel. Professional travel is built around the meeting and convention markets. These markets have grown as transportation, especially by air, has become more available and affordable. As professional travel continues to grow, new and expanded meeting and convention facilities have been developed to satisfy this increasing demand. Along with this growth, new management challenges have arisen to serve this specialized market. Some of the key market segments for meeting participants or attendees are associations, businesses, exhibitions and trade shows, religious organizations, political parties, and governments.