Could the ice bucket challenge be the biggest online charity campaign of all time? The answer is, probably.
With Patrick Stewart, Matt Damon, Idris Elba, George Bush, Bill Gates and even Homer Simpson recently taking part, the ice bucket challenge is already the most-mentioned charity campaign on Twitter in the past 12 months.
As the name suggests, the social media phenomenon sees people pouring a bucket of ice-cold water on their head and filming it for charity.
Participants donate money to charities which support Amyotrophic Lateral Sclerosis or ALS (referred to as Motor Neurone Disease or MND in the UK).
This figure is 20 times more than Twitter mentions for the #nomakeupselfie craze, which saw women posting selfies of themselves “bare-faced” without any make up earlier this year.
The millions of Twitter mentions for the ALS challenge are merely the tip of the iceberg: there have also been many mentions of the stunt's other hashtags such as #ALSicebucketchallenge, and posts on other social media platforms.
Nearly 2 million videos have been posted of YouTube and the video of former US president George W Bush taking the challenge has received 3.7 million views on one ALS channel.
In fact, the craze is so big that it's difficult for analysts to measure.
"This is a hugely popular meme that's been distributed across many different video platforms," says David Waterhouse, the head of content for social media company Unruly Media.
"We've not seen anything like it since the Harlem Shake. It seems like anyone who owns a bucket and camera phone is taking part right now, which is great news for the charities involved. Tracking all instances of the ALS Ice Bucket Challenge is a mammoth job as instances span every social video platform.
How did the ice bucket challenge start?
There is some dispute over how the challenge began - but it definitely wasn't originally to support ALS/MND. For the last few months, sports groups such as golf players have been posting videos of themselves being covered in iced water, sometimes just for fun and sometimes with the requirement to donate to a charity of your choice. What is agreed is that the moment it reached the mainstream was when former profession golfer Greg Norman challenged NBC anchor Matt Lauer to complete the stunt in July.
The stats available show the ice bucket stunt looks set to dwarf the challenges that have come before it...
The annual facial hair-growing season has become an institution. Men suddenly sprouting a mustache (and sometimes removing it swiftly in December) is de rigeur in the 11th month of the year, in aid of prostate cancer.
In the past 12-months, #Movember has received 1,658,950 mentions on Twitter – and one in every eight of these was from the UK.
Movember is one of the few campaigns to achieve longevity beyond the initial craze: Events run by the Movember Foundation have been running for 10 years, but the momentum is still building.
Global Google searches for the term "movember" have got higher each year, with the most interest in founding country Australia, followed by the US and UK.
Despite extensive media coverage, the #nomakeupselfie hashtag has only been mentioned 221,488 times on Twitter. The movement – which was not started by Cancer Research UK but was adopted by social media users as a way to donate money to the charity - raised at least £8 million.
The video about African war criminal Joseph Kony was created by charity Invisible Children. It aimed to have Kony - a fugitive of the International Criminal Court - arrested. It still holds the record for the most-shared charity film of all time on YouTube, according to social media company Unruly Media.
A more modest success in terms of Twitter mentions, Find Mike was launched to help schizophrenic Jonny Benjamin track down the kind stranger who persuaded him not to jump off London's Waterloo Bridge in 2008.
Find Mike had 67,065 mentions worldwide, according to We Are Social, and Jonny was reunited with the man he called "Mike" in January 2014.
Dubbed the “world’s most important social media campaign” by gay website The Gaily Grind, #cockinasock was a response to #nomakeupselfie, and asked men to pose with a sock over their penis.
The risqué stunt was to raise awareness for testicular cancer. The hashtag #cockinasock was mentioned 53,565 times on Twitter around the world, according to We Are Social.
Macmillian Cancer Support’s attempt to encourage people to either shave their heads or restyle their hair in July fell rather flat in terms of social response, with only 1,816 mentions on Twitter and a mere 271 followers for the campaign’s Twitter account.