You could also mention the number of web sites dedicated to cruises (not including the ones from the lines themselves). That alone will open some eyes as to how popular cruises have become. Many many many (33 to be exact) I did a presentation on cruises for a public speaking class I took in college. It was as easy as cake once I got into it because of the love of cruising. I think the title was "To Sea or Not to Sea -That is the Question". I compared the cost of a week on the cruise ship to a week at a resort. Got an A.