Mobile Today reports that the vast majority of smartphone owners are paying for a data allowance far in excess of what they actually need. Given that it's almost impossible to estimate data usage in advance (you're far more likely to stumble upon a data hungry app than suddenly massively increase your calling minutes, for example), what would be a fairer way of charging customers for data?

I'd like to see a tiered and fully-automatic charging system. An example tariff might be:

100MB data included FOC
Up to 500MB data @ £2.50
Up to 1GB data @ + £2.50
Unlimited data @ + £2.50

As the user breaks through each barrier they could receive a text message alerting them that they have been charged an additional £2.50 and how much data that allows them.

Not only is this fair on low data users and high data users by ensuring each pays a fair amount respective to their usage, but it also means that those with sporadic usage patterns need not try to second-guess this and adjust their tariffs in advance. An 'unlimited' price band is important because I'm a strong believer that a price ceiling to the consumer encourages take-up of data-based services by removing the risk of an unexpectedly high bill.

I shouldn't imagine this structure is too attractive to the mobile operators as it'd almost certainly lead to a loss of revenue from low-data-usage customers. Such a mechanism may, I believe, already exist on some networks, though in a much less tiered and more punitive, rather than helpful, way.