Kevin Rose: Digg Failed Because 'Social Media Grew Up' - Digits - WSJ

Another NoSQL case study

"The final nail in the coffin, said Mr. Rose, was that Digg became hobbled by technology problems as the site tried to move to a new database system on the fly around the same time as the summer 2010 re-launch. Since Digg was having problems in scaling its MySQL database software, it began to shift over to another open source system called Cassandra.
“We launched with broken code,” he said. “There is nothing worse than screwing up and not being able to fix it. There was no Amazon Web services back when we launched. It would be a lot easier to build Digg today.”"

Kevin Rose: Digg Failed Because 'Social Media Grew Up' - Digits - WSJ