While the flash mob phenomenon started as an experiment in the power of online chatter, the advertising industry quickly embraced it and used it to promote products, causes and organizations. Can you distinguish the mobs that were born of genuine passion versus marketing?
This event was put on by professional organizers, but they did it out of love for the show, with the goal of making people smile.
There's so little information of any kind on why this was done, but there's no product in the picture to promote.
On this occasion, more than 13,000 people gathered for the Thriller dance out of love for Michael Jackson, and their effort made it into the book of Guinness World Records.
Though there's no question that the dance crowd of 20,000 people was there largely out of love for Oprah, it was a great marketing tool for the popular television show nonetheless.
This flash mob was actually an ad for T-Mobile's "Life's for Sharing" campaign.
This mob was inspired by T-Mobile's "Shout" flash mob that took place only a month earlier, but it wasn't created to promote any particular product or brand. However, it drew such a huge crowd that the station had to be shut down.
This flash mob appears to have simply been a tribute to Shakira's anthem written for the 2010 FIFA World Cup.
A concert promoter set out Beyonce lookalikes to promote the singer's free concert in November 2009.
This was actually an Oxfam campaign to increase public awareness about the danger facing women giving birth in third-world countries without access to health care. It was repeated in other major European cities and in Canada.
This flash mob was organized by Improv Everywhere, a collective that has sponsored public pranks in New York City since 2001.