What are some of the best social media campaigns of all time? What makes them the best?

As social media continues to grow and users flock to new websites every day, it's become impossible to deny how beneficial Facebook, Twitter and LinkedIn are for marketing your business, and that's to say nothing of burgeoning networks like Google+ and Pinterest.

These sites have massive followings which you can easily tap into by starting a social media marketing campaign and expanding your company's digital reach.