Jul 25, 2014 · 3 minutes

When we think of social networks from a brand, publisher, or celebrity perspective, Facebook, Twitter, Instagram, and maybe Pinterest rise to the top of our mental lists. They are open, public, and permanent, or as permanent as anything else on the web. It makes sense then to leverage these networks to reach as many people as possible, as often as possible.

But there's an entire other netherworld of social media that is harder to measure but according to some data even more powerful: dark social.

The theory of dark social, as presented by Alexis Madrigal, posits that the pioneers of the social web were not Friendster or Facebook -- they were instant messengers like ICQ or AIM, AOL chat rooms, USENET forums and other message boards, and of course, email. This is the kind of social media that's not so easily quantified -- you can't "like" an email or Gchat (though I often wish I could).

The best way to tap into this dark social movement is not always clear. Certainly most publishers send newsletters and brands send out direct email ads all the time, most of which languish under the "Promotions" tab on Gmail. And because you must view them within the more utilitarian bounds of an email app client, they are usually hard to read, especially if brands try to get too clever from a visual standpoint. That's hardly a very engaging experience. Also I'd be more creeped out than starstruck if my favorite magazine or brand invited me to Gchat.

But then there's an app like Snapchat which, with its blend of dark social and light social attributes, we might call "gray social." On one hand, the app's traditional use case is to send ephemeral messages to select people -- a cornerstone of dark social. On the other, Snapchat recently launched Stories, a tool to broadcast to all a user's contacts longer, more involved collections of photos and videos that last 24 hours. Yesterday, TIME profiled a handful of "viral Snapchat stars" who have racked up millions of followers and in some cases make up to $100,000 a week helping companies produce branded content.

In the right hands, Snapchat's interface and production mechanism can be a powerful tool. Stories are optimized for mobile consumption, an area advertisers are still trying to crack. Plus, the ability to combine video, photos, and drawings into one ad unit opens up a wide range of creativity that is obviously lacking in traditional mobile or banner ads, and also missing from, say, Instagram or Vine alone. Jerome Jarre, a 24-year-old who somewhat obnoxiously calls himself an "outgoing Borat Frenchman" tells TIME that while his Instagram following grew by 800,000 in 18 months after joining Vine, after just three weeks on Snapchat he gained 1.3 million more followers on the famous filtered photo network. Snapchats may not leave a permanent mark but the community's network effects are still undeniably strong.

Of course the concern over not having a permanent record of an ad unit is not invalid. That said, social marketing svengali Gary Vaynerchuk told TIME, “Why anybody thought that a disappearing piece of content isn’t valuable is insane to me. Last time I checked, when I’m listening to a car commercial on Z100, that shit disappeared.”

As a marketing or promotional tool, Snapchat may still be a fad. And engagement there is more difficult to measure than on Facebook or Twitter where publishers can count shares, likes, clicks, and retweets. In any case, Snapchat has delivered a wholly unique form of creative expression with a consumption experience unlike anything else. And if the company wants to ever bring in actual revenue, it better find a way to convince advertisers that it's more than just a toy.