Its not really a "sect" thing, its in the Bible to go out into the world, streets included, and spread the Gospel to people, like the Apostles did.

See: Luke 14:23 and well, basically anything the Apostles and Jesus generally did and where they generally preached and taught, in the midst of the people in public spaces.

In terms of effectiveness, that's a difficult thing to say, but saving people isn't a numbers game, though obviously its better when more are saved. If even one person's soul is saved by it, it had value.