http://mashable.com/2010/06/21/principles-viral-media-site/

There’s a good chance that you’ve come across the word “meme” at some point or another in the past few years. It’s an arcane academic concept but at the same time it’s also one of those things that you can identify, but can’t describe easily. Richard Dawkins coined the phrase in an effort to help explain cultural evolution in his 1976 book, The Selfish Gene, where it’s defined as a shared element intended to be passed around within a culture, a societal analog to a gene. Now, even though it may not be immediately apparent, there are a number of universal qualities that all successful viral memes have in common.

TweetMeme Community Contributor posted about a year ago