I think the best way is to replace individual services that Facebook provides with unbundled superior ones. For example the way WhatsApp succeeded was among oth

I think the best way is to replace individual services that Facebook provides with unbundled superior ones. For example the way WhatsApp succeeded was among other things by using the phone number as the unique identifier, that way especially signing up and starting to use the App was significantly easier than manually adding all your "Friends" again. Another example would be Instagram. Obviously Facebook realised the threat in both cases and bought them. The underlying idea is that focussed "minimalistic" apps are easier to use than kitchen sinks like Facebook, especially on mobile devices. On top of that mobile phones already come with some sort of "social network" build in, everyone has the telephone number of people and businesses that matter to them. So the attempt of most big web companies to provide people with a "web identity" is mostly misguided in this case. With the advent of ipv6, hopefully it will be come pointless on the web as well. The remainder of todays "Social networks" will then probably be just a very well organised and feature full address book on your personal devices.