There are a bunch of points in this entry on debris that are great, but this is my favorite: “It stopped mattering whether the feature was even useful to the visitor. We ask our visitors to ‘Digg This’ not because it adds any value to their experience, but because we need the traffic.”
That’s always really bothered me about those “bookmark this” or “Digg this” buttons. If someone already uses Digg or del.icio.us they know how to bookmark your site. It just feels so icky.
Anyway, go read the whole thing.