We're working on quite a few things in this same area right now and would love to hear any feedback and suggestions on what you'd like to see on ReadBurner.

The Twitter follower count is an interesting one because everyone said they lost a bunch of followers the other day...seemingly because Twitter cleaned out some spammers.

Here's what feedburner is: it's a proxy your blogs rss feed that adds some features. In particular they track how many people are "subscribed" to the feed (presumably they use some heuristic based on number of "GET" requests). They also expose the feed to other tools, such as search, and simple web-based methods to read the feed.

In many ways, it reminds me of a simple Google Analytics for feeds. You can't use GA for feeds because there's no JavaScript host at the receiving end to ping google when someone reads an entry. So services like Feedburner have sprung up, and which perform the service for the small cost of introducing complexity into your blog: after all, if Feedburner (or it's competitors goes down), so does your feed. (And I guess that's why the Goog acquired Feedburner!)

There's also the issue of data mobility - Feedburner has the potential to gather a lot of information about how your feed is accessed, but it's not clear who 'owns' that information.

This is all part of the growing pains of the new internet, I suppose. Back in the day this issue never would have come up - if you wanted to know who was reading your stuff you'd check the apache access logs!