In one of the most pronounced examples of "What not to do to your successful website," Digg updated their site to version 4 despite overwhelming community rejection. Stubbornly keeping the update while citing that "bringing something as radically different as Digg version 4 was bound to generate a strong reaction,"link Digg inadvertently sent a majority of their userbase to reddit by community backlash.
Digg v4 had a new dynamic that removed emphasis on user contributed content and provided twitter-like follow streams from websites that users could subscribe to. A lot of users felt as though this move was to generate revenue for the site, as it strongly promoted content and blog sites that drew a large amount of their traffic from Digg (such as Mashable.com). Upset digg users, already having to deal with a small community of powerusers who found ways to game submissions to their front page, performed a massive exodus to reddit. Reddit users spammed digg with reddit links just prior to the sites change.
Reddit, already above digg in users and visitors, acted as refuge for internet users who wanted too easily find and watch viral videos. Reddit, who at the time was never the smaller sister site of Digg, surpassed Digg in popularity in August and September of 2010.
The effect this had on reddit as a community has been a large point of debate. Some veteran users of the site reacted unfavorably while others tried to welcome the new users. Regardless, the effect has been very pronounced. Reddit's traffic grew threefold in 2010, a large portion of that increase can be attributed to Digg v4's redesign.