Great point! I agree, once a system becomes really huge it becomes hard to maintain and centralized system which used to be efficient becomes inefficient. Howev

Great point! I agree, once a system becomes really huge it becomes hard to maintain and centralized system which used to be efficient becomes inefficient. However when the system CAN be maintained they are generally more efficient IMO. For example many developing countries go through a stage where the government makes a centralized plans. Even the U.S. went through this until the point where the scale itself brought forward inefficiency. However when it comes to an internet service like Twitter which CAN be maintained in a centralized manner--at least so far--I don't think decentralized approach has any benefit in terms of efficiency :)