Shares: 2.1 million This coffee shop gets paranormal as part of a marketing campaign for Carrie.
Shares: 418,023 The title really says it all, here.
Shares: 320,611 GoPro offers another epic outdoor video showing off its product.
Shares: 258,145 It wouldn't be a most-shared ads list without the Geico "Hump Day" ad.
Shares: 241,781 It may not have as many views as the other GoPro ad, but this video of firemen rescuing a kitten is far more moving.
Shares: 237,310 Samsung's Galaxy Note 3 and Gear smartwatch launch was one of the biggest tech events of last month, and this hands-on video got passed around quite a bit.
Shares: 225,156 Leave it to Crest to ruin Halloween by pushing healthy treats to kids.
Shares: 205,327 Virgin America's sassy airline-safety ad will make you dance in the aisle, which might be counterproductive.
Shares: 187,677 What do birds have to do with Mercedes? We don't know, but this ad still makes us smile every time.
Shares: 178,099 Pepsi created a mini-movie about a pair of old men who show up a group of young kids on the basketball court.
Shares: 164,278 This animated short will make you want to head down to the nearest comic shop.
Shares: 129,566 Learn valuable life lessons, such as "Don't poke a stick at a grizzly bear."
Shares: 129,451 This may not be quite what the late Lou Reed had in mind when he wrote "Perfect Day," but it makes for a fun ad.
Shares: 107,560 Nothing is quite what it seems in this Honda ad. You'll want to watch it a couple of times.
Shares: 105,386 The animated series pays tribute to Top Gun.
Shares: 104,431 If you've been using Playstation since the early days, you'll get a kick out of this ad.
Shares: 82,734 LG uses a chicken to show off its new stable cameras.
Shares: 78,988 This concept video touts the idea of an environmentally friendly phone that could be taken apart into blocks. As it happens, Motorola unveiled a similar concept recently, called Project Ara.
Shares: 74,749 Microsoft recruited some celebrities, a giant robot and a zombie to promote the launch of Xbox One.
Shares: 71,181 These tots have moves.
Every brand hopes its ad will go viral. A viral ad means more eyes, more media attention and, hopefully, more revenue. But there's no perfect formula for making an ad more shareable, and the many brands who try don't often succeed.
These 20 ads make it look easy, racking up thousands of shares on YouTube in the last month alone.
See also: 20 Funny Tweets Your Brand Should Take Seriously
The list, compiled by Unruly Media, has everything from daredevil GoPro stunts to replaceable technology. There are also a few reigning champions from last month, like "Girls Don't Poop" from Poo-Pourri.com, and Mercedes-Benz's dancing chickens. "Dumb Ways to Die," the year-old Melbourne Metro ad, even made a comeback.
Click through the gallery to see which of your favorite viral ads were shared the most in October.
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Image: Youtube, CarrieNYC