• by Lisa Lacour , Op-Ed Contributor, July 23, 2015

So you think you know "Brooklyn mom" right? She does yoga, maybe some Pilates, peruses mommy blogs and is overly concerned with whether her food is truly organic. She can easily be reduced to a stereotype, which many marketers still turn to, even though plenty of them care more about the NFL than DIY.

There are also probably others who, like me, love to play Magic: The Gathering, a super-nerdy card game played mostly by 12-year old boys.

And you probably also think you know what men between 18 and 21 are like. They enjoy beer, gadgets and bathroom humor. But how then do we account for the roughly 10 million college-age males who are avid fans of “My Little Pony”? Are these “Bronies” just weird outliers?

Intuitively, we know demographics don’t tell the whole story of a person.

Still, ad targeting is reliant upon it. And while the notion of the “interest graph” – effectively an invisible map of what people online are interested in based upon their behavior – has been touted for at least the last five years, it’s been challenging for marketers to tap into effectively.

But here’s the good news. That’s changing – gradually – because of more sophisticated uses of data.

Back in 2011, or a generation ago in Silicon Valley time, social networks like Facebook and Twitter were thought to have a monopoly on the emerging interest graph. But we eventually learned as an industry that social actions such as a Facebook “like” or a Twitter favorite were superficial forms of engagement that didn’t necessarily mirror users’ true affinities.

Version 2.0 of the interest graph isn’t predicated on what people “like,” but what they actually spend time doing and seeking out. For instance, it turns out that reading is a much better proxy for true interest and engagement than “liking.” It’s also why “attention metrics,” where publishers charge advertisers based on the time people spend in an article instead of impressions, are gaining traction.

This shift in the industry’s understanding of how the interest graph really works helps explain the deals Facebook recently struck with publishers like The New York Times and Buzzfeed to host their articles inside its walled garden. The goal – for Facebook – is to better understand what its users are reading and, implicitly, what interests and moves them to ensure they spend more time on the social network.

It also helps explain why Pinterest is currently building a big ad business that’s based largely on the specific content that users are seeking out and discovering on the platform. It’s proving effective because the promoted pins people see when they search for something like “wedding gifts” are basically the same as what would come up organically.

Despite the fact that technology now makes interest-based targeting at scale viable, most digital campaigns are still built around demographic insights. And a big reason for that is just our natural desire as marketers to be in control.

Since we live in a world ruled by ROI, focusing on the knowns (tangible demographic facts) over the unknowns (enigmatic interests) makes perfect sense. It helps explain why we gravitate towards programmatic advertising platforms; we can target, hyper-target, and slice and dice data until we think we’ve reach our intended target demographic.

But we still may be failing to reach huge audience segments – like 10 million Bronies – by failing to use technology to map out people’s interests.

Interestingly, I’ve been noticing instances of brands taking their prospective customers’ hidden interests into account in their product development and marketing strategies. For instance, who knew there was a sizeable market in delivering beauty (or “grooming”) products right to men’s doorsteps?

Birchbox didn’t start its business with that premise, but over time, the company conducted enough research and validated enough assumptions to launch a Men’s line, which appears to have paid off. A more long-standing example is Pabst Blue Ribbon beer, or PBR as it’s known to the hipsters who saved the brand from demise and whom it now markets to.

We’ll see more marketers doing deep research into the real interests of their customers – to target ads, to develop new products and even to guide core business strategies. Brooklyn moms are still there; they just don’t have all that much in common with each other when you look below the surface.