I think that GDI can be used in any market. Start first with niche you understand. For example I am web site builder, fitness instructor and martial arts teacher so I am targeting webmaster who would like to save some time and stop building websites the old way - trading time for money, the same is personal fitness trainers - I believe if they are not online, they cannot effectively communicate with their clients.
So just do something everyday. What about tell 2 people a day about GDI. At the end of the month its 56 people in the funnel - if only 5 do something its good. Don't you think guys?
Brett