In 2009, Dave Carroll (a professional musician from Nova Scotia, Canada) engaged a massive worldwide audience to share his customer service story about United Airlines. Using YouTube.com to deliver his message, he wrote and performed a song that has made an impact. Some people estimate 100 million people saw his video.
You see, United Airline broke his $3500 guitar then rejected his request that they pay for it. But after his video went viral United changed their corporate mind and offered to reimburse him. (You can see the video below.)