On the first point, you only need to include a summary of the resource for notification purposes. The idea is that the user still visits the site to consume the

On the first point, you only need to include a summary of the resource for notification purposes. The idea is that the user still visits the site to consume the actual content I am not sure what you mean with the second point, the timing of updates is under the full control of the content creator no? The third point is quite relevant. Some sites ask that you subscribe to get updates (via email). Obviously they want to have better visibility of their audience rather than have a large set of passive (lurkers). That is a legitimate choice.