Last month, The Guardian delivered a “seismic” piece of news that got publishers everywhere to rethink the value of social traffic when it announced that Facebook had overtaken Google as its primary source of traffic. Today, we have another example of Facebook’s traffic-driving prowess, this time in the e-commerce sector.

The evidence is becoming hard to ignore: we’ve seen video and social become a driving force in the growth of digital advertising, highlighted again by this morning’s IAB numbers and last week’s landmark study on ad effectiveness. Combined, social+video represents a £443 million market in the UK alone. It’s no surprise then that New York-based Buddy Media announced today a new social marketing integration deal with YouTube.

The IAB UK’s latest tally is just out this morning and again the figures make for bullish reading material. Once again, the digital ad growth in the UK is experiencing crisis-defying growth, and the fastest growing part of that is social media marketing. Let’s dig into the numbers.

Despite grumbling by the average Joe Facebooker over the new Timeline design, a new study by Simply Measured suggests that the new Facebook style has boosted brand content engagement by a hugely significant 46 percent.

Your teenage nephew’s homemade videos may not win an award for creativity, or even clarity, but don’t dismiss the power of these amateur auteurs. A new ad effectiveness study shows that user-generated videos more than pull their weight when compared to the pros. They even drive sales.

We’ve taken up this question a few times now here at SMI: should the boss be Tweeting? And the answer always comes with the phrase “it depends…” as in, it depends, is the CEO a sociopath? or, it depends, is the CEO a fictional figure? If you check these boxes, it’s best to keep the boss far away from Twitter or any social media channel. But here’s fresh evidence that should serve as added incentive for organizations to groom the next boss from the ranks of lucid Tweeters.

We saw earlier this month some of the clearest signs yet that marketers have shed their reservations for investing in social media, committing to upping the spend in the coming year. Now, a new study shows that the most social-savvy companies are using social engagement to expand marketshare, generate more sales leads and more efficiently hone their marketing message.

Twitter notified us this evening it is gradually rolling out to small businesses – a huge force in the world of social commerce, it turns out – a “self-serve advertising product” called Promoted Products for Small Business that delivers potential sales leads to SMEs active in the mobile and social space.

If you were to sum up the philosophy of spirits marketers in two words, surely, it would be: sex sells. Could social media change all that? If the Belvedere Vodka PR mess that erupted on Twitter and Facebook over the weekend is any indication, then the creative guys better figure out some new bright ideas to sell booze and spirits.

It’s been just over two weeks since the aptly named, under-the-radar NGO Invisible Children released to YouTube a classic piece of agitprop video, KONY2012. And what a two weeks! The video has been viewed more than 100 million times and Invisible Children have been lauded for their actions in shining a spotlight on the atrocities carried out in central Africa by Joseph Kony, leader of the Lords Resistance Army. At the same time the very success of KONY2012 has shone an equally bright spotlight on both the finances of Invisible Children and the factual accuracy of the video.