April was always going to be a tough act to follow.  Last month's record-breaking chart saw Dove's ‘Real Beauty Sketches’, Kmart's ‘Ship My Pants’ and Evian's ‘Baby & Me’ dominating talk across the social web – the first time ever that three commercials from the same month have also featured in the top 20 most shared ads of all time.

It was always going to be hard for new social video campaigns to break through during May. And so it proved, with the same trio taking up three of the top five spots in this month's list.

Created by Ogilvy Mather and attracting more than 738,000 shares during May, Dove's record-breaking Sketches campaign – now the most viewed and the third most shared ad of all time - retained its number one spot last month.

Evian's dancing toddlers are also showing no signs of fatigue, moving up one place to second, while Kmart's Ship My Pants' fifth spot – and the success of its follow-up campaign, ‘Big Gas Savings’ - proved people are not tired of hearing haulage-based puns...just yet.

However, some new campaigns made it on to May's top 20, including four for Samsung’s new smartphone, the S4.

The most popular video of the quartet promotes the new Sound & Shot feature, which brings a totally different meaning to the phrase, “a picture says a thousand words”. In fact, the S4 goes one better – by also being able to speak. Confused? Let me explain. You see, Sound & Shot allows you to record sounds with your photos.

So when you are travelling and you want to share your experiences with friends or family back home, they can now enjoy not only the sights but the sounds of your travel destination. Whether they plan to add smell to your pictures in the near future is unclear.

The ad brings this to life with a touching story of a mother and her globe-trekking son keeping in touch through this fun new product. It certainly did the trick, attracting 572,739 shares last month, making it the third most shared ad during May.

But it wasn’t just the Sound & Shot feature that had people talking about the new S4 last month.

In 14^th position is a video which showcases another S4 feature, ‘Group Play’, which allows you to play your music on your friends' phones, while seven places above that is ‘Hands On’, a 13-minute walkthrough of all of the new S4 features and product specs.

Of course, it seems no Samsung Mobile launch is complete these days without at least one jab in the ribs of its biggest rival, Apple.

The South Korean tech giant did the same thing last year to help launch the S3. The Next Big Thing Is Already Here, created by 72AndSunny, was a hugely successful milestone campaign launched in September which brilliantly lampooned the cult of Apple, portraying its fans as mindless groupies. 

Although not quite as popular, ‘Graduation Pool Party’ - in which the out-of-touch parents are the ones with what suspiciously looks like iPhones while the teens are the ones with the cool new S4s - is another biting attack on Samsung’s fiercest competitor. 

The message of the video is summed up in one quote, uttered by the granddad. He says, "So what you are saying is some smartphones are smarter than others. So what are we doing with these phones?"

It’s a message that certainly resonated across the social web last month. The ad attracted more than 82,000 shares during May, putting it in 19^th position.

Microsoft even got in on the act last month, releasing an ad for its new Windows phone, the Nokia Lumia, which attacked both Samsung and Apple fans. It was a bold move, but one which paid off, with the commercial managing more than 220,000 shares last month, putting it in 12^th spot.

Another video to boldly go into the upper reaches of the Unruly Viral Video Chart last month was Audi’s ‘The Challenge’, which pitted two actors who have played Spock in Star Trek – Zack Quinto and the legendary Leonard Nimoy – against each other in a battle over who can get to the golf club quicker.

Admittedly, driving to the golf course is not as exciting as say a fight over who has the better Vulcan death grip, but then two Spocks for the price of one - how could any self-respecting sci-fi fan resist? And so it proved – with the ad’s 566,013 shares last month putting it in fourth.

The ad also benefitted hugely from being released when excitement around the release of the new Star Trek into Darkness movie was at its zenith.

However, the real success of this ad is that you don’t have to be a die-hard Trekkie to enjoy it. Sure, there are no doubt a number of in-jokes that whistled past my head faster than a spaceship in warp speed, but that didn’t matter.

The banter between the two very likeable and popular actors is very entertaining and the pay-off was worth sticking around for.

Other ads to feature in this month’s top 20 include a couple of Mother’s Day spots from P&G and Nivea, the ‘World’s Smallest Movie’, created by IBM, another hilarious local commercial from Rhett & Link and three videos promoting the most highly-anticipated videogames of the year - Call of Duty: Ghosts and Grand Theft Auto 5.

Top 20 most shared ads during May 2013 (Facebook, Twitter and blogs)

1. Dove: Real Beauty Sketches – 738,150

2. Evian: baby&me – 641,070

3. Samsung: Galaxy S4 - Sound & Shot – 572,739

4. Audi: Zachary Quinto vs Leonard Nimoy – The Challenge – 566,013

5. Kmart: Ship My Pants – 463,904

6. Activision: Call of Duty – Ghosts Reveal Trailer – 415,988

7. Samsung: Galaxy S4 – Hands-on – 304,422

8. Activision: Call of Duty – Ghost Masked Warriors – 297,044

9. Kmart: Big Gas Savings – 296,003

10. Nivea: Mama – 280,145

11. Samsung: Usain Bolt - 228,044

12. Microsoft: Switch To The Nokia Lumia – 220,765

13. Arlen’s Transmission Centre: Shift It - 215,836

14. Samsung: Group Play - 202,642

15. IBM: A Boy And His Atom - 177,455

16. Rockstar Games: Grand Theft Auto V – 176,903

17. Melbourne Metro: Dumb Ways To Die – 175,033

18. P&G: Maria & Eunice Shriver – The Gift My Mother Gave Me – 97,994

19.Samsung: S4 Graduation Pool Party – 82,237

20. Red Bull: Mad Mike – 75,232

Until now, 'prankverts' have mostly exploited the format's comic potential: Coke Zero turned commuters into super-spies and Swisscom tested attention span with hilarious results. But Leo Burnett's arresting new spot pushes the trend to more dark and poignant territory.

Working with the Department of Transport's drink-driving campaign, THINK!, the ad uses fly-on-the-wall cameras to capture the inside of an average pub. Without background music or context, we see members of the public entering the toilet.

But first a disclaimer: we recommend watching the spot before reading too much about it, as its genius lies in its shock value. Viewers of a sensitive disposition might also find the ad slightly upsetting, but this feeds into its attention-grabbing message.

In any case, we'll say that 'Pub Loo Shocker' employs a special effect as ingenious as it is terrifying. With this card up its sleeve, the ad is an exercise in simplicity. Just a couple basic camera angles, a grisly noise and Leo Burnett let the participants' horrified faces do the rest.

There is a tradition of using horror-film tactics to deter drunk-driving, with THINK! regularly producing some of the most disturbing ads around. With 11,000 shares already since its launch on June 6, 'Pub Loo Shocker' definitely delivers the kind of jolt that gets people talking. 

Terrifying pub-goers and viewers alike, this ad certainly has the potential for shocking the public out of complacency. 

So you're thinking of bringing in a famous star to help boost your new advertising campaign.

It makes sense, right? Sure, it’s not going to be cheap. Beyonce’s Pepsi deal was reportedly worth $50M to the singer, while Coca-Cola and Blackberry recently splashed out on multi-million dollar endorsements for pop stars Taylor Swift and Alicia Keys respectively.

But a bit of celebrity stardust can make any ad campaign sparkle, right? Stars such as Beyonce, Swift and Keys have millions of followers on Twitter and Facebook just itching to share their favourite star’s latest project - even if it is an advert.

Well, not as much as you might think actually. Sure, popular wisdom says celebrity endorsement is a tried-and-trusted way to maximise your marketing effectiveness.

But if you visit the Unruly Viral Video Chart and scan through the top 50 most shared ads of all time (rankings and stats from June 1, 2013) it’s a very different story. In fact, you’ll probably find more ‘stars’ on a trip out to a local Nando’s in Penge (it’s in south London). OK, I exaggerate, maybe a few more than that, but you may be surprised by how few ‘celebs’ you do find.

That's right folks. Coming to a town near you (if you live near Antwerp, Belgium) is a magical vending machine that doesn't want your dimes, pennies or euros, but your friendship - on Facebook that is. 

Pepsi take technology and social media by the hand and combine the two into a 'Pepsi Like Machine'. It's pretty safe to say it does it excactly what it says on the tin.

Lucky fans at a Beyonce concert in Antwerp were the first to test out the latest marketing campaign from the combined efforts of Pepsi and TBWA Belgium. Pepsi claims the fans loved it, and judging by the footage in the video, plenty were more than happy to trade Facebook likes for a refreshing can of Pepsi. 

This concept further embelishes the fact that 'social' is currency for top global brands, especially the likes of highly competitive Pepsi and Coca-Cola who have broad global product offerings.

However, the CPG giant takes a refreshing approach at learning more about their fans and rewarding them for their brand loyalty. Will we see more of this sort of thing in the future? We expect so. In a highly-contested market place, brands will look to take bigger, broader steps to stay ahead of the competition.  

The video, which launched yesterday, is yet to reach the social video masses, with just 2,488 views and 481 shares at the time of writing, according to Unruly Viral Video Chart data.

Will this approach capture many new fans? Well, we certainly think it's a refreshing idea, but only time will tell. Watch this space.