Ad:Tech, the self-described 'world's largest gathering of digital marketers,' came to a close today after three days of keynotes and breakouts at New York City's Javits Center.  The focus, as you might expect, was social advertising: how the best brands are leveraging networks like Facebook, Twitter, and (now) Google+ to expand their businesses and reach new customers. 

In case you missed it, was there to pick up on the biggest ideas—from digital advertising to social networking—that need to be on your radar today.

People Don't Care About Your Brand. They Care About Their Friends

"In reality, people don't want to 'Like,'" Michael Pranikoff, global director of emerging media at PR Newswire, told the audience at the panel on social media, referring to Facebook. "They want to love. Why would someone share [on Facebook]? It's not because they like your brand. It's because they like their friends."

In other words, it's not about how many Likes you get on Facebook or how many followers your company has on Twitter—it's about creating content that people actually want their friends to know about.  One popular phrase floating around the conference was "social by design." That's the idea that advertising campaigns need more than great material--they need to be centered around your customers and relate to their interests, desires, and personal challenges.

"People don't want to talk about your brand," echoed David Rosenberg, director of innovation at LBi US, a brand agency based in New York. "They want to talk about the things that interest them."

For example, when Sony Ericsson was looking to promote their new phone, the Xperia, they knew the advertising had to be social by design. Rosenberg, who worked with Sony on the campaign, says that the company thought of the phone not just as a communication device, but as a tool that would help customers see the world in a new way. That's why Sony partnered with Joshua Peek, an astronomer at Columbia University, to build "The Invisible Universe," an Android app which uses GPS position and device orientation to reveal what's happening in the universe—from massive black holes to constellations—right on the Sony Ericsson platform. The app, launched over the summer, has been downloaded nearly 50,000 times, and it has generated scores of positive reviews, from Gizmodo to Wired. That kind of attention, says Rosenberg, "brings discussion about a product to a new level."

Narrow Targeting Should Actually Be Narrow

For all businesses, a major advertising consideration should be searching out the customers who will find your product or service relevant to them.

So let's be honest: Facebook pretty much blows it out of the park when it comes to narrow targeting. You can target by age, location, education, interests, and employment history. But you can also target to customers whose conversations include words like 'puppy' or 'baseball.'

Before Facebook, hitting your 'narrow target' (e.g. engaged female customers between the ages of 24 and 30), meant targeting customers with about a 35 percent rate of accuracy. Now, with Facebook targeting, you can hit your demographic with about 90 percent accuracy.

To be sure, it's not just about a targeted paid approach, says David Fischer, VP of advertising and global operations at Facebook. Rather, you want to use both targeted and broad campaigns and a fully-flexed company Facebook page.

"The key point is that the sum of the parts is greater than the whole," Fischer noted on Wednesday's keynote speech. "When you put them together, you get virality."

Demand Accountability from Advertisers

Gone are the days when you let a campaign fly and hope for the best. Whether your campaign is purely digital or mixed media, don't let advertisers push you around on the analytics. You need to know the ROI of your ad campaigns.

Andy Fisher, an executive VP at Starcom MediaVestr, says that one of the biggest flaws right now in online advertising is analytics—80 percent of the time advertisers are tweaking reporting errors caused by conflating metrics such as 'site visitors' with 'page views' or 'unique visitors' with site traffic. They only spend 20 percent of the time actually tracking the numbers, he says. But it's not an excuse. 

"If you run a campaign that's targeted to moms, and you ask 'How many moms did you actually reach?' the advertiser deserves to know the answer to that," Fisher told the audience at the Data panel.

Optimizing for Search? Great. Now Optimize for Social.

"Just like you optimize for search, you need to optimize for social," Dave Linabury, said director of interactive experience at Campbell-Ewald, speaking on a panel about social media. Linabury says the most innovative brands are beginning to audit their sites and finding new opportunities to encourage sharing of products, services, and content. That doesn't mean just slapping a Facebook or Twitter icon in the corner of the page and hoping people click it, either.

Take Levi's, for instance. Up until last year, the site merely allowed users to tweet or 'like' the brand's main page. Now, shoppers can 'like' specific pairs of jeans, recommend products to their friends on Facebook, and even comment about products using their Facebook handle. The site also (very cleverly, I might add) connects with Facebook Birthdays to remind you which of your friends may be celebrating birthdays soon—so that you never forget to buy a present ever again.

Don't Be Afraid to Break Convention

Colin Westcott-Pitt, the VP of marketing for Dos Equis, helped create "The Most Interesting Man in the World," one of the most memorable and successful ad campaigns over the last couple of years. The ads generated some 2 million Facebook Likes and several million views on YouTube. So sure, the ad seems brilliant now. But in the beginning, Westcott-Pitt says the ad was met with plenty of skepticism.

"A lot of advertisers felt we broke the rules by hiring a 70-year-old-guy [for a beer commercial,]" says Westcott-Pitt. "But the whole bloody thing took off. It doubled the brand's growth rate—and its market share." 

Plenty of other brands have had some pretty notorious flops. That shouldn't stop you from taking risks, although, as Westcott-Pitt says, "It definitely takes guts."