When it comes to toppling web giants, one factor is frequently overlooked: The replacement is usually radically different from its predecessor
This year, Digg entered a decline after a series of stumbles, and some users were said to defect to rival Reddit. And yet the site's troubles really began much earlier, with the rise of Twitter and Facebook. Although radically different in their execution, these two social services served much the same purpose as Digg by allowing users to share interesting links they found around the web. As web users found new outlets for these behaviors, Digg's relevance dwindled.
The real threat to Digg wasn't a clone but rather a completely different approach.