Advertisers love Snapchat's priciest ad format - and that ought to worry its social media rivals

It's hard to think of many ad formats - particularly online ad formats - that people not only actively engage with, but send to all their friends.

But Snapchat has cracked it.

For Halloween 2015, Twentieth Century Fox became the first marketer to run a Sponsored Lens campaign. Snapchat users taking a video selfie could overlay images of characters from "The Peanuts Movie," while its theme tune played. When users opened their mouths, "an endless stream of candy corn" poured out, Adweek reported.

Snapchat confirmed to Business Insider that it has run more than 50 Sponsored Lenses campaigns in the seven months since launch.

Some 30 million snaps each day are now decorated with Lenses (of all kinds, not just those paid-for by advertisers,) up from the 10 million reported earlier this year.

And the small batch of advertisers that have paid to be among those 30 million decorated snaps can't get enough of them.

Views are through the roof

At a cost ranging between $100,000 up to $750,000 for 24-hour Lenses tied to specific holidays and events, according to several sources familiar with Snapchat's ad pricing, Sponsored Lenses are the most premium ad buy on the app.

It's a premium ad buy for the web too - a 24-hour Promoted Trend on Twitter for example, tends to only cost in the tens of thousands of dollars, those ad buyers said.

Not only that, but it's a very manual process.

There's no other ad unit like it, so advertisers and agencies need to spend time working with Snapchat to make their Lenses happen - they can't just re-purpose their other online ads and make a quick decision to buy. Instead, advertisers and agencies submit their ideas to Snapchat, which goes ahead to create mock-ups of the animations itself in-house, which then go back to the brands to approve.

But advertisers are pleased with the results so far.

Earlier in May, Taco Bell achieved the record amount of views for this Sponsored Lens:

The Lens was viewed 224 million times and the average Snapchat user played with it for around 24-seconds before sending it on to their friends, Adweek reported.

Gatorade launched an ad to coincide with the Super Bowl earlier this year. It allowed user to dunk a cooler of Gatorade over their heads, honoring the big game's tradition to soak the head coach of the winning team in the soda.

The brand holds the record for engagement with a Sponsored Lens. The Super Bowl Lens was interacted with for an average of 30-seconds by each user who sent it on to their friends.

In the UK, confectionery brand Cadbury was so pleased with the success of its Creme Egg Sponsored Lens campaign in March, that it launched a Sponsored Lens for its Crunchie brand this Friday.

Jerry Daykin, global digital partner at Cadbury's agency Carat said: "Lenses drive significant reach of an audience you would struggle to buy on TV. When you get it right, the average time people use [a Lens] can go up to a minute; it's very personal and very energetic."

He added that some influencers, including Zoella, shared the Creme Egg Lens with their followers - adding even more earned media that Cadbury didn't even need to buy.

Jason Stein, founder and CEO of social media agency Laundry Service, has been running third-party research to assess the success of the Snapchat Sponsored Lens campaigns it has launched for its clients.

"We've been testing on things like brand lift and recall and it's been really positive. It's very telling, even amongst an older demographic," Stein said.

Why it works

Both Daykin and Stein agreed the reason Lenses work so well for brands is that they are fun.

Stein said: "It's funny because you don't think of a goofy taco face as a premium ad buy; you'd probably think of a beautiful HD video. But they're really fun and I don't think you can point to many types of ads and say 'wow, I had a fun time with that ad.' And in having fun, people are becoming brand ambassadors for you, sending it to all their friends with your brand on their face."

The "fun" element may also be the format's biggest hindrance. Creme Egg is a fun, colorful brand - but it might be harder for a bank or a sexy luxury brand to find the perfect Lens.

It's worth bearing in mind that not all of those 50 Sponsored Lenses have managed to go viral - only a few have managed to really pick up. And as more brands start experimenting with Lenses, there's also the question of burnout.

Daykin said: "The disadvantage is that it's harder to tell a specific message. It's more just something fun to do with your brand to raise awareness, and a lot of brands will struggle with that. For us, we're cautious to get too carried away, especially if Snapchat raises prices to the point where it gets questionable. At the moment, it's really exciting, but will they get boring after time after we see a few of them?"

As has been leveled at Snapchat in the past, many marketers will also demand more data from the app - beyond soft metrics like views or engagements - about how Sponsored Lenses actually impact their bottom line.

"They're doing everything right"

Snapchat has made big improvements in this area, working with third-party measurement firms including Nielsen and Millward Brown to provide marketers with metrics including views, reach, completion rate, and brand resonance.

Those updates seem to be working. Unilever's marketing boss Keith Weed said earlier this month that after a while of experimenting and "failing" with Snapchat, the app has now "come of age." Marketing Week reported that 500,000 views of a campaign for its Cornetto ice cream brand led to "ROI [return on investment] through to sales - we sold more stuff," Weed said.

This summer, Unilever is running a Sponsored Lens across six European markets for its Magnum ice cream brand as part of its "Release the Beast" campaign:

Sponsored Lenses are not likely to be Snapchat's biggest revenue-earner any time soon. At most, there will only be one or two Sponsored Lenses in a market on any given day and the manual way they need to be bought (not to mention pricing) compared to its more-familiar video ad formats and sponsorships will probably mean that won't change any time soon.

But it's exactly the fact that Sponsored Lenses are so different from any other format out there that gives Snapchat a big advantage over its rivals. Snapchat has tried where others have failed to create a mobile ad format that uses the functions of the smartphone and that people actually want to engage with. Users are checking back each day for new Lenses - and it appears they don't discriminate between those that have been sponsored or created solely by Snapchat.

Stein said: "Snapchat has started a big trend in binding the utility of communication with fun in a way I don't think I've seen before. You look at something like telecoms or TV, they never thought how do we infuse fun and not make it cheesy or corny. But this is Snapchat's core ... they're doing everything right."