Since Google Reader started showing how many people subscribe with its service to different RSS feeds there’s been a lot of talk and analysis about how many subscribers different blogs and sites have. However one element hasn’t been talked about that much – the fact that many blogs have multiple feeds and Google Reader doesn’t combine them all into one result to give you a true number.
Most of those analyzing the data don’t seem to be looking at multiple feeds.
For example – here at ProBlogger there are two main feeds that people have subscribed to – the original ProBlogger feed and the Feedburner one:
Andy picks up the ‘why’ and ‘how’ it could be useful to have these two figures in his post The Secret Statistics In Split RSS Feeds – Google Reader.
Matt Cutts points this out too and also reminds us that blog software like WordPress creates many feeds – including feeds for categories, comments etc.
Update: Pete Cashmore also makes a strong case for these sorts of numbers being compromised by ‘default feeds’ such as Google Readers ‘bundles’ which he says will inflate your figures by around 50,000 simply by being added to a bundle.