In June of 2005 +Jeff Jarvis posted a rant on his blog Buzz Machine titled "Dell lies. dell sucks" www.buzzmachine.com/archives/2005_06_21.html
That post sparked a customer revolt. Dell's market cap has deteriorated ever since. Certainly the customer discontent from 2005 is not the only reason for Dell's difficulty. But I'm sure it was a factor. Dell today takes Social Business seriously, with one of the most sophisticated social listening command centers on the planet.