I will come across as an ass here because I think it is time that Social Media Marketing gets recognition.

SEO is about ranking in search engines, traffic and conversion.
SMM is about using social media for traffic and conversion.

Yes this video ranked well in search engines for certain terms but the reason it got popular was through social media, not search engines.

I agree that there are 5 key elements for creating a successful content in Social Media:

authentic
positive
emotional
featuring real, recognizable people
short

I think the best element is the 3rd one, “emotional”. Watching the wedding dance video, you can’t help but smile. You get emotional but it was also because the whole party was emotional in the video. The wedding party is having a blast and you feel like you are having fun with them.

This is not the first wedding dance/surprise video. One of my favorite is a couple’s first dance on Jack Johnson which turned into Michael Jackson – The Way you Make me Feel

However, the JK wedding video is more emotionally packed by the people performing in the video.

I will add a 6th and 7th element to yours: originality and surprise.

The video of Norm and Renee’s Wedding First Dance has been done. Walking down the aisle like that? I have never seen it on YouTube.

I also have to add that timing is very important. I think that the video I metionned earlier would of been as big as the JK video but 2.5 years ago, people were not sharing like they are now with Facebook, Facebook was not at its current size, neither was Twitter, etc.