The exercise is fairly simple -- take a concept, a category, or simply an idea and then list all of the assumptions about it. Then take each assumption and list the exact opposite of that assumption. And then use those reverse assumptions to ideate.
The question for hotels and other travel suppliers is reaching that market online -- a task that seemed daunting in the earlier days of the Internet because of the "complexity" of an event -- all the logistics of many people getting together in one place at one time.
Attend enough social media and digital marketing conferences and common themes soon emerge.