Digg can be described as an ecosystem for news readers and contributors. That ecosystem is usually thought to be both wide and deep. But below is snapshot of just how critical (and influential) the top 50 users are to it - the icons with a yellow banner / star in it are from my Digg friends (all top 50 users). See a trend? A close friend of mine ran a test on Digg by befriending the top 100 Digg users. His first 3 submissions made the front page within their respective category… He had submitted 100s of articles before and this was a first. As the power users move - so do the herds.
This raises the questions, what happens if the rumored Microsoft acquisition actually happened? Does Digg work if it’s top 50 / 100 users flee? Flickr had similar questions when MS announced their Yahoo bid… I would argue though that Flickr’s value is more sustainable without its core users than Digg’s is.