The Marriott Corporation is in the following businesses, among others:

• Hotels of different types
• Long-stay residential hotels
• Luxury resorts
• Time-share properties
• Airline catering
• Institutional food services
• Franchised operations
• Credit card tie-ins
• Travel operations

Given the above listing, would you say that Marriott’s business lineup reflects a strategy of related or unrelated diversification? Explain your answer in terms of the extent to which the value chains of Marriott's different businesses seem to have competitively valuable cross-business relationships.