If ever there was a time of transition for the online advertising and publishing industries, this is it. With consumers being exposed to more and more ads each year--one estimate  posits that, on average, we each see roughly 5,000 ad messages per day now--in 2013 brands will be challenged more than ever to find and reach their next viable customer prospect. Meanwhile, publishers will find themselves fighting equally hard for the shrinking attention of consumers.
With all of this in mind, what moves can we expect advertisers and publishers to take in the coming year?
First, while “social” and “mobile” get a lot of lip service, we’ll see smart publishers and brands embrace mobile and social technologies to an extent they haven’t in the past. And, when it comes to social, I’m referring to all forms of online communication--not just Twitter and Facebook. Secondly, while quality “content” has long been the key differentiator for publishers, these companies will begin to leverage their content and data in new ways to attract and keep readers. Finally, I think many publishers and advertisers will rejoice in the fact that the poorly conceived Do Not Track campaign of the past two years is about to come to an end. With that said, here are my five predictions for 2013:
1. Companies will begin to leverage “dark social” to drive sales. Today, there is widespread confusion regarding social media’s impact on online sales. IBM, for one, recently stated  that less than one percent of Black Friday e-commerce sales were driven by traffic from social. Part of the problem is that IBM--and frankly most of us--define “social” only in terms of Facebook and Twitter. In reality, some sites get 30% of their traffic from email and IM, which is usually mis-categorized as “direct navigation.” This powerful form of word-of-mouth marketing--what might be more accurately defined as “dark social”--remains a major blind spot for publishers, brands, and commerce companies, inhibiting their ability to measure a key driver of sales. In the coming year, brands will become far more equipped at detecting and accounting for this viral feedback loop: link sharing, site traffic, and ultimately, purchase.
2. Brands will get serious about social. While every major brand is embracing social advertising, 2013 will be the year in which marketers will gain a significantly more in-depth and sophisticated understanding of how their customers communicate with each other online. For instance, brands will begin working harder to understand the types of channels and devices through which consumers are sharing information, and when and how these cumulatively effect sales. Given that mobile is expected to grow significantly in 2013, this laser focus on unlocking the social/mobile combination will separate those brands that succeed from failures.
3. The multi-channel advertiser will prevail. The explosion in the number of consumers engaging with brands on mobile and tablets will force advertisers to become significantly more “mobile aware.” The success of advertisers will no longer be only predicated on creating the right ad and targeting the best audience. Rather, advertisers will need to think more strategically about usage patterns and multiscreen activity. For instance, advertisers will need to closely examine how users increasingly navigate and consume branded content on smartphones and tablets, versus the desktop.
4. Content marketing will hit its stride. It has long been said that “content is king.” And, yet, online brands--publishers and advertisers--are just scratching the surface in terms of leveraging content to attract new readers. In the coming year, content creators will increasingly lean on data to gain a much keener understanding of who is sharing their content, what they’re sharing, and even why. These editorial insights and analytics will allow publishers to, in turn, encourage greater distribution of their content by readers, leading to more traffic from every channel, and ultimately, revenue.
5. "Do not track" will die a final death. Over the past year, a number of privacy hawks and academics--through the W3C’s TPWG working group--have tried to force a "do not track" policy that would effectively kill online advertising, and consequently, end the free Internet. In 2013, however, it will be the TPWG that will meet its maker. Consumers have made their choice clear: They want relevant advertising, they want relevant deals, and they want to continue to enjoy a free, ad-supported, Internet.
Get ahead with more insight into 2013 in the Fast Company newsletter. 
--Eric Wheeler is the CEO and cofounder of 33Across . Prior to 33Across, he was the CEO of Neo@Ogilvy and Executive Director of Ogilvy Interactive North America. Eric’s career includes leadership positions at CNET, Young & Rubicam, and Anderson & Lembke in San Francisco.
[Image: Flickr user Thomas Leuthard ]