Given the task definition and input, reply with output. In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Article: The lce Bucket Challenge, in which people dump a bucket of ice water on their heads and challenge others to do the same, has brought in millions of dollars in donations for the ALS Association, and is among the biggest viral phenomena 2.4 million vides related to the ice bucket challenge have been shared on the social network, and more than 28 million people have posted, commented or liked a post relating to the challenge. "Marrying the Internet's love of challenges with donation and charity is _ ." Said Neetzan Zimmerman, a former editor at Gawaker who's widely considered as an expert in viral phenomena. "There is no other way to say this--it's absolutely pure brilliance ." The nature of the Ice Bucket Challenge is, in itself, quick in spread. "People want to look good to others, so it's hard to turn down a prosocial cause," said Jonah Berger, an author of Contagious: Why Things Catch On. "ALS is a great cause, so when someone asks you directly to do this, it's hard to turn them down without seeming like a bad person." The Ice Bucket Challenge campaign has been great for the ALS Association, a non-profit organization that does research and provides help for patients with Lou Gehrig's disease. It has received $ 22.9 million since July 29 and the donations are coming not only from existing donors, but from nearly half a million new donors. Celebrities have been interested in the cause, which has undoubtedly accelerated the spread. At this point, it's almost difficult to find a celebrity who hasn't had ice water dumped on his or her head. Kobe and Lcbron have done it and Bieber has done it twice. "If you are doing, it's as if you could stand in for them," said Jennifer Cool, an anthropologist at USC who studies Internet culture and history. "You can be in the shoes of Lady Gaga or Bill Gates, too." And, of course, there's showing off factor, Internet is a place to show off and promote yourself, filled with incredible vacation photos, reminders to all that you're in love with challenges. You may have some friends who've seemed eager to show off their bikini or swim trunk bodies in their Ice Bucket Challenge videos. At this point, some celebrities seem to be trying to one-up each other. Bill Gates released a highly produced video of himself designing a method of dumping water on himself. Hockey player Paul Bissonnette, for some reason, had a helicopter drop glacier water on him.
Answer: Because it spreads quickly.
Why does the author call the Ice Bucket Challenge a viral phenomenon?