Just about every semi-organized christian church has a mission-based component to their ministry. A lot of folks tend to go out and do the typical schools/wells/irrigation system thing, and slip the locals a copy of the Bible when they can.
Others see it as a spiritual vacation, in which they can get into a better, cheaper climate, and feel good that they're doing God's Work.
That said, many of these mission trips are quite well-funded, and travelers are often willing to pay (or fund raise) a premium for the experience.
From the video, it sounds like he's going to serve as a sort of liaison/expediter, and make all the arrangements for the teams coming in. Think of it as a sort of combined travel agent and project manager for small to mid-sized groups of people coming in for weeks at a time, once or twice a year, every year. It would be seasonal work, peaking during summer vacation for school kids. During the rest of the year, their time would be their own. And each one of those groups would prefer to do business with someone like-minded.
They could actually do quite well with that business, much better than some dude opening a bar in Sosua Beach.
A number of folks already do this. The key is having the church contacts back home.
Dominican Republic Mission Trip through Praying Pelican Missions