One comment has come up every time I’ve given my RSS, ATOM, OPML, and All That talk. As soon as I describe RSS/Atom as “push”, I know a hand’s going to shoot up and some techie is going to say, “But isn’t the feed reader polling the server every 30 minutes to pull down the content?”, and my response is always, “Yes, it is; but that’s irrelevant.”
The issue is one of point of view, and the only point of view that counts here is the user’s. The user does not have to take any extra action to get the updated content. It shows up in their reader automatically. This is push. From the user’s point of view, they are not pulling anything. The user really doesn’t care how the different combination of software running on their machine and the server interacts to push the content to them. All they care about is that happens without any effort on their part. In fact, it’s possible to imagine a serverside blog client that does automatically push updates to a browser client using server push or AJAX. I doubt that would be as nice an experience as the current clients, but there’s no technical reason it couldn’t work.
RSS is push just like e-mail is push. Whether you use Eudora, Outlook, or Thunderbird; POP or IMAP; the messages actually get into your inbox because your client goes out and pulls down the messages from the server. (They may be pushed onto the server in the first place, but they’re always retrieved via pull.) As long as the e-mail client pulls down the messages without a specific use request or action, it looks to the user like push and that’s all that matters.