Tours are a chance for the Royal Family to shore up support for the monarchy in Commonwealth nations, or strengthen diplomatic and trade tides in other countries. As de facto British ambassadors, all trips are carefully planned to maximize potential.
The emphasis on personal connection and interaction means that tours grant a more relaxed view of the royals than fans usually get in the average two-hour engagement.
William and Kate have already undertaken several blockbuster tours, including their first overseas tour to Canada, and briefly to Southern California in 2011, and an almost month-long trip Down Under in 2014.
From a fashion perspective, tours are also times when Kate is more likely to debut new pieces, and explore labels native to the host countries.