This is not a problem with a simple solution. People can handle Twitter (one-way subscriptions); people can handle Facebook (reciprocal friendship.) But they

This is not a problem with a simple solution. People can handle Twitter (one-way subscriptions); people can handle Facebook (reciprocal friendship.) But they are annoyed at having more than one service. Which one is the winner? Which one replaces the other one? If I drop one then I abandon all my contacts on the other! Argh! The easy technological solution is a site that offers complex, configurable relationships, but can people handle it? Probably not, or at least, not yet. So we have reached the current equilibrium of multiple services, with Facebook the winner, and a minority of people choosing integration or choosing to manage accounts separately on more than one service. Perhaps the day will arrive when people are ready for more sophistication in managing relationships on a social networking site. If Facebook times it right and adds relationship configuration options at roughly the right pace, they can stay on top and supplant Twitter entirely for social networking. Or perhaps the current situation reflects the limit of what people want to cope with. I'm sure Facebook is researching the question and deciding which way to bet.