"But over time, Digg changed. Redesign after redesign unnerved loyal users. Finally, one new version, v4, was so atrocious that there was a mass exodus from the site altogether. The new site was a disaster both visually and content-wise, as “sponsored links” were thrust onto the front page and users felt like they were being packaged and sold to companies.
So where did all these disgruntled users flee to? Well, as most of them were already using Facebook and Twitter for social reasons alongside Digg, Reddit was the obvious choice. The balance of power tipped into the simpler site’s favor, and as Digg became more and more irrelevant, Reddit was growing by leaps and bounds."