I think the best example for why this is useful is described by david glasser at his talk about the oplog driver used in meteor.js https://www.youtube.com/watch

I think the best example for why this is useful is described by david glasser at his talk about the oplog driver used in meteor.js https://www.youtube.com/watch?v=_dzX_LEbZyI https://www.youtube.com/watch?v=_dzX_LEbZyI