It's really no surprise that so few are involved, since usually all they could do anyway would be to send a check to strangers in a distant city, or perhaps sit thorough an occasional boring meeting. They are busy with their own lives and seldom have the time or know-how to investigate the organization they would be contributing to, or to learn enough about the issue to feel confident in writing to a newspaper. (And if they do contribute or write the letter, what then? What is the next step?)
The biggest reason by far that so few people are doing anything to make a better world is the lack of usable "structures of involvement."
And what are structures of involvement made of? Primarily they consist of practices for communication and interaction. A movement experienced in the arts of developing practices could custom-build structures of involvement for the needs at hand. The practices would be designed to benefit participants immediately, as well as benefiting others far away.
Today, "cause" organizations (at least outside of direct human services) usually do a terrible job of providing non-specialists with graceful, intelligent, and meaningful opportunities to participate. Communication practices could be a laboratory for developing better ways. If they are successful, they will catch on.
Could humanitarian causes become as popular as sports, revolutionizing the human condition? We see no reason it could not be done.