Our friends over at mSpoke -- with whom we're collaborating for related content and post-popularity data -- have a very interesting post up on their blog called "What Makes a Blog Post Popular?" 

In this illuminating post, mSpoke's Paul Ogilvie teases apart what aspects of feed items correlate to their popularity; specifcially, he dives deeply into NewsGator attention data and makes some very interesting and incisive conclusions (one of which can be seen at right).  I hope you'll take a look at this excellent post.