Valleywag has an excellent Cheatsheet on What is Digg? Basically, if someone asks you what is Digg, just send them there. It describes the basics, how it works, how to break it, Digg's competitors, the recent publicity on Digg, "How Digg fits the buzzwords," oh and don't say "I got digged," I believe it is "I was dugg." Full details on Digg at Valleywag.
Optimising Digital Marketing Campaigns with Search, Social and Analytics
At SES London (9-11 Feb) you'll get an overview of the latest tools, tips, and tactics in Paid, Owned, Earned, Integrated Media and Business Intelligence to streamline your marketing campaigns in 2015. Register by 31 October to take advantage of Early Bird Rates.