Thanks to the great help by Rick Klau, VP, Publisher Services, FeedBurner, the problem I raised earlier today in a blog post has been identified.

According to a post by the Microsoft RSS team, Outlook 2007/IE7 should identify themselves in the HTTP request of an RSS feed as “Windows-RSS-Platform/1.0″ when requesting subscribed feeds. Rick determined though that Outlook 2007 B2TR identifies itself as “Mozilla/4.0″, which is the user-agent string used by IE7 when a feed is just browsed to. Therefore all subscriptions from Outlook 2007 didn’t get counted, but rather recorded as hits by a webbrowser. I will keep you updated.

Update

As most of you probably know, Outlook 2007 and IE7 have built-in RSS support. In fact, they use the same RSS engine. If you want to know more about Outlook’s RSS support, then check out the blog of the Outlook program manager for this feature.

If you provide an RSS feed for your blog, then there is a good chance that you use FeedBurner. FeedBurner is a great tool to get accurate statistics on how many subscribers an RSS feed has for example. Unfortunately, FeedBurner doesn’t count any subscriptions from Outlook 2007 or IE7. It looks like FeedBurner just doesn’t know that Outlook 2007/IE7 can be real RSS readers. This is a pretty annoying problem for me, as I would assume that a large number of you are subscribing to my blog via Outlook 2007.

With over 3.5 million downloads of Office 2007 and I don’t know how many of IE7 RC1 and Vista, this is not just a minor issue. Hence, if you use FeedBurner, your subscription number might be too low as well. Let’s hope that they recognize this problem and fix it soon.

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