I think the problem Facebook has is once someone uses it for a few years there's a potential that they'll get sick of it. When someone gets sick of a site like

I think the problem Facebook has is once someone uses it for a few years there's a potential that they'll get sick of it. When someone gets sick of a site like Facebook they rarely if ever go back. Since it's a social network that results in a lot of lost value and degrades the experience for other users who may have friends leaving the site.