Among the best case studies is UPworthy, who've made viral content their business.
The site pulls together the best video on the web and packages it in a bundle of awesome. Chosen videos see a massive spike in viewership as UPworthy regulars watch then share with their networks.
The key to this consistent virality? Choosing content that is more than just cats and people falling over. Their content is both amazing AND meaningful. It’s got heart.