Since the advent of movable type, and well before, the point of media was permanence and pervasiveness. You took the time to publish something because you wanted as many people to consume it for as long as possible. Self-destructing content is antithetical to that spirit. If someone had told Gutenberg that he could print his bible, but the whole thing would crumble to dust in 30 minutes, he probably would have stuck with being a goldsmith.
Yet for personal communications, particularly in the digital age, privacy is a precious commodity. Between that dynamic and the gnat-like attention spans of many users, an app for short self-destructing private messages was bound to take off.
The big question was (and is), how do you monetize a platform like this? Slapping banners into the app or injecting screen-takeover units into chats were never real options. The Snapchat audience has grown as fast as it has because of the intuitive and simple user interface, and ad clutter is certain doom for that kind of experience.
Some brands have started their own accounts for people to follow. The brand can then broadcast content to enthusiasts. It's a way to reach Snapchat's coveted young audience, and the right creative approach can certainly make an impact. That said, practically the same creative idea could be ported over to Twitter, Vine or Instagram; it doesn't take advantage of what makes Snapchat special.
Meanwhile, Snapchat's Our Story product combines snaps from people at a geo-specific event into one continuous montage that vanishes after the event: the company's answer to "appointment television." With this feature, brands have an obvious opening to sponsor events and creatively insert themselves into what emerges as the user-generated Story of an event.
But back to Discover, which has opened up a whole new realm of marketing possibilities. Its user interface is simple and built around swiping; left to go forward, right to go back etc. Discover is an intriguing rethink of the mobile web experience. Responsive design is great and all, but this kind of interaction is gaining steam (as with Tinder). Instead of starting with the Web or TV and asking "how do we adapt this for mobile?" Discover is a "mobile-only" content experience by design.
We have now entered the age of brands telling stories 10 seconds at a time, with each episode expiring after one day. Brands can eventually look to create their own channel in the app's media portal. Addictive branded, self-destructing content could be a big draw. The key is creating a sense of authenticity, and feeding FOMO (fear of missing out).
Snapchat is about what's happening now or very recently. Old news feels out of place. Within Snapchat, users expect quick hits of ephemeral content before they bounce off to the next thing they care about. Brands can probably pull off powerful campaigns on the platform if they get the creative right and remember the audience to whom they are speaking.