Imagine a world in which the apps on your phone all carried different fees. Want to launch that Facebook app? It will cost you 2¢ per megabyte of data you exchange with the social networking site—but launch Skype, and you might find yourself billed a flat monthly rate. And preferred apps would incur no charges at all, no matter how much data is exchanged.

As for the money, it's paid not to Skype and Facebook and YouTube, but to your mobile data provider, who wants a piece of the action passing over its network (and who wants to avoid becoming an undifferentiated "bit hauler").

This vision of the mobile world is feasible today, thanks to deep packet inspection gear and some robust policy creation tools. With the right hardware and software, carriers can exert fine-grained control over billing that goes well beyond the money-for-total-bandwidth-model seen increasingly today. Of course, to critics, "fine-grained" sounds like "nickel-and-diming," and they see it as little more than an excuse to turn an open Internet into something more like a cable system, complete with different access "packages."

This vision was on display in a webinar yesterday, one given by DPI vendor Allot and billing company Openet. The topic was "Managing the unmanageable: monetizing and controlling OTT applications." OTT means "over the top," and it refers to apps that use the Internet to reach consumers. The problem (or "problem") for wireless companies is that many of the key apps come from extremely lucrative businesses; why shouldn't the operators be able to use the size of their customer base to charge these companies some money?

Slide 7, seen below, gives an example of how this might work.

Want Facebook? Get ready to pay—or not; as a further slide makes clear, one of the key business models here might be bundling connectivity with the app. In other words, the Facebook app would come with, say, unlimited data use while the YouTube app would not. Wireless carriers could charge Facebook a fee to provide this "free" data use to consumers.

Free Press was aghast at the presentation, which shows "the potential real-world consequences of Chairman Julius Genachowski's proposal to explicitly allow mobile wireless operators to violate the long-standing principle of network neutrality. The unholy alliance between these two companies and wireless carriers is a sneak peek at the future we can expect if the Commission passes policies that divide the Internet along mobile and fixed connections—a market defined by business partnerships built around nickel and diming consumers and controlling the pace of mobile app innovation."

One obvious potential problem with switching from an "open Internet" approach to this "charge by app" approach to data is just how much power it gives the established players. Say some new video on demand service comes along; it needs plenty of bandwidth, but it can't afford to strike a deal with carriers so that its app bandwidth is free to users. How many users will even try it out when an app from Hulu or Netflix is free (to them) to use, while accessing the startup will cost them money?

The potential upside to users is a smaller data bill. If Google paid to cover YouTube bandwidth on mobile platforms, consumers might get away with smaller data plans. But given that the goal is to increase revenue, and given that we've seen these arguments made before, color us extremely skeptical that any real fee reduction will be forthcoming.