Dark social - sharing that occurs in private messaging environments - has been a hot topic in marketing and tech circles for a while now.
Last year some incredible data from BuzzFeed and USA Today's viral sports site, For The Win, showing the rise of WhatsApp and decline of Twitter, for mobile sharing, sparked even more interest in dark social.
With both of these new sites appearing as pioneers in dark social, marketers took note, seeking to learn new tricks to exploit this new frontier of digital marketing.
Nearly a year on, what have these news pioneers continued to learn at the bleeding edge of dark social? What new insights can we marketers learn?
BuzzFeed: an empire built on viral sharing
It wasn't much of a surprise to see the folks at BuzzFeed pioneering in dark social. The growing BuzzFeed empire is built on viral content and social sharing and it continues to teach most other news publishers how to do social.
When BuzzFeed launched its mobile WhatsApp sharing button last year it instantly drew more clicks that the Twitter button. This got tongues wagging amongst marketers, as people sought to understand what it really meant.
But what has BuzzFeed learnt over the last year we should take note of?
I checked in with Ben Ronne, Product Lead for Growth and Data, to find out more.
Ben told me that the percentage of clicks on the WhatsApp sharing button continues to trend upwards, almost doubling since it has been enabled on Android. Interestingly, the most significant growth in WhatsApp sharing has occurred in UK, Brazil and Germany.
We should also note that whilst WhatsApp buttons have been drawing growing numbers of mobile clicks, other social buttons have not.
"Over the last six months, total WhatsApp shares have almost doubled while BuzzFeed's total email, Facebook and Twitter shares have remained relatively flat."
So it seems the stunning power of WhatsApp sharing continues to reveal itself for publishers like BuzzFeed.
BuzzFeed generally appears ever more recognisant of the opportunities of dark social, with Ben telling me that they've "recently partnered with WeChat and Viber to help grow and engage with our rapidly increasing international audiences."
For The Win: taking sports content viral
Alongside BuzzFeed last year, in the digital marketing chatter on dark social, was For The Win (FTW). Being another viral content driven business this also wasn't' surprising, and Jamie Mottram, Director of Content Development there, kindly replied to my questions with a gold mine of insight.
"What we saw initially with WhatsApp last spring and summer held true throughout the year, which is to say that: FTW's mobile users were using WhatsApp sharing tools more often than Twitter sharing tools, with Facebook and email sharing tools remaining on top at one and two, respectively."
However, in late 2014 FTW decided to try a new move in dark social, replacing the Twitter button for mobile and replacing it with SMS sharing.
The results of this experiment blew Jamie and his team away.
"The early returns were staggering: The SMS button was being used three to four times more often than the Twitter button was. Three to four times!"
Since then, the new SMS sharing button has proved even more popular with FTW mobile users than the WhatsApp button, with both proving far more popular than Twitter.
Jamie also advised that FTW's experiments with dark social had proved so successful that "one month into the latest share tool configuration, it looks like overall taps on FTW's mobile share tools have increased between 30-40%".
At FTW, whilst Facebook remains the most powerful individual button, dark social actions taken in aggregate are now a majority of mobile shares.
Dark social clearly has a massive role for disseminating the viral content that Jamie and his team invest so much time in.
Balancing the growth of mobile and dark social with your own realities
It seems the growth of mobile browsing, combined with increasing numbers of instant messaging app users continues to drive the growth of dark social. WhatsApp is one of the fastest growing channels within this.
This is a major opportunity for brands that move to smartly exploit these new channels, build new relationships with customers and unlock even greater virality in their content.
Nonetheless, marketers also need to be mindful of their own local considerations.
Different sectors, platforms and content may all need different sharing options.
We've specifically looked at news sites here, offering content with potentially inherent virality. Marketers in financial services, or pet care, might find notably different behaviours and trends.
Nonetheless, dark social is a huge digital ecosystem, becoming less dark by the day. How are you moving to optimise for it?