(unless someone stupid gets behind the wheel of the policy machine)
Look people, stop complaining about your cell phone bandwidth. It will ALWAYS be slower than your WiFi connected to a dedicated land-link, and it will ALWAYS be slower wherever their are more users because that's the inherent nature of a full coverage infrastructure. No wireless service provider (including the WiFi at your local coffee shop) guarantees all your packets will arrive untouched and in order at server X in time Y. That's the nature of a packet switched network. That's what you're buying. You're buying access to the Internet, the same as anyone else. Sure some pipes are bigger than others, but there you're buying a MAXIMUM based on the technology involved in the first link, not an assured amount of data to your destination. And even the first link must necessarily be shared on a wireless platform-- there is no wire and only so much band in the spectrum. And what about total data? Well, should a rural 1000MB user pay a huge tiered price, even though the 1000 one meg users in the city are the ones actually influencing the slowdown? Fair billing under a tiered system is impossible, if fair is defined as those who cause more congestion pay more, as pegging an individual as causing a quantifiable amount of congestion (or "unfairness to others") is impossible, or at the least not inexpensively computable. Buying an Unlimited data plan means you have the FREEDOM to use however much you need. This comes as close to fair as possible, as everyone has equal opportunity, those who cause congestion are frequently punished with a slowdown by being within the congestion themselves, and prices for the unlimited plan are set based on usage by the entire AT&T customer base. As long as AT&T holds up their side of this, it stays a largely self regulating system. You are paying the cell company to do their job and put data towers where they are needed most (i.e. assuring congestion slowdowns are not overly punishing), and for your FREEDOM from the tedium of managing data. The burden for managing the bandwidth supply is best placed on the cell company-- the ones who understand it best --whereas adding a tiered system moves the burden to the consumer, where it wastes time and is managed poorly. If a person has to think about whether they really need this extra megabyte of data they are about to consume in an application, then inevitably revenue will go down as less apps are used and less contracts signed, and at the same time value to the consumer is lost because every megabyte carries an extra burden of wasted time. Lose-lose.
To go back to the first paragraph, cell companies would be more successful if they stop treating the consumer as an infinitely rational computation machine that can make sense of a 100-page bill. Yes, the lack of freedom in a tiered package would kill the magic of the iPhone, if by magic we mean convenience of a stress-free billing environment. Anyone who has taken their iPhone to another continent knows that watching every megabyte and regularly hassling with AT&T over international billing really takes the fun (and productivity) out of iPhone use. To AT&T's credit, the only customer service problems I have ever had with them were all related to International billing-- and I have been with them before the iPhone, before even Cingular. Nonetheless, it had a huge impact on my usability and satisfaction while I was out of the country. if I had to do that here, I would drop the iPhone.
In other words, likewise and conversely to the previous point, cell providers will have less angry support calls and phone contract rage-quits if they stop abusing customers' very same inability to comprehend said 100-page bill, often abuse involving false charges and misspoken sales information-- a problem compounded by their own staff's strain in managing the every changing and increasingly complex billing policies.
In short: Keep It Simple, Stupid.