It's such a great initiative. We really need it in this part of the world (Africa, Nigeria) where we hardly can make available an accurate estimated population of our citizens. We don't have a database as a nation.
My Opinion, the process has to be crude and mechanical. Because most of these places are not reached with internet services, the roads are hardly accessible and the level of illiteracy is too high. So, it would take a lot of sensitization, house to house meetings and so on to get it done.