[qw]

> RSS is great but it has one great flaw in that it doesn't scale that well by itself

The readers often cache the result for all users of the same feed. The only exception are readers that are running 100% locally. In that case using Etag or Last-Modified will make each request cheap and manageble.

[AndrewStephens]

That is my point. RSS by itself is a scaling problem but online readers make it manageable by polling sites on a reasonable rate and redistributing new articles to their users.