The next time you queue up to buy an iPad, 3G wireless broadband dongle, or an Android phone or tablet, ask yourself: why are the data plans so expensive, when they deliver so little?

The latest broadband study from the Australian Bureau of Statistics tells us that servicing the data needs of mobile broadband users requires only one-fourteenth the network capacity of Australia’s fixed broadband users – even though mobile broadband now makes up 47 percent of the total Internet customer base in Australia.

Although mobile broadband accounted for 90 percent of new connections added in Australia between June 2011 and December 2011, fixed lines remain the engine-room of downloads in the country.

That’s the conclusion behind the latest release of the ABS’s Internet Activity, Australia report, released on March 30.

As the number of mobile broadband services neared 5.5 million, the “fixed broadband is dead” brigade came out in force, declaring that the growth of 3G-enabled devices rendered Australia’s fibre-to-the-home National Broadband Network obsolete and unnecessary. After all, while the mobile sector added more than 700,000 new services in just six months, DSL, fibre and cable only managed 85,000 adds.

It’s a thesis that works, and will probably be picked up by the federal opposition and other NBN opponents – right up to the point where you look at users’ download behaviour.

Downloads flatly contradict the "don't need fixed networks" narrative.

Since June 2010, in spite of mobile connections now outnumbering fixed connections, the proportion of downloads using fixed connections has risen – from 91 percent of the total to 93 percent. Mobile downloads, formerly 9 percent, now represent just 7 percent of the total.

The raw three-month total downloads reported by the ABS are fairly impressive: Australians downloaded more than 345,000 Terabytes in the three months to December 2011.

Fixed users' download growth, however, is nothing short of stunning: since the December 2009 survey, when the average Australian fixed user downloaded 8.75 GB per month, fixed downloads per user have nearly tripled to 22.7 GB per month.

At the same time, mobile per-user downloads – in the face of new plans that offer more suck per buck – have actually fallen slightly, from 1.67 GB per user per month in December 2009 to 1.4 GB per month.

To look at this another way: to service the entire fixed broadband population in Australia, carriers and ISPs need more than 300 Gbps of capacity, nearly triple the 116 Gbps that serviced fixed users in December 2009. Mobile users today can be served by a nearly-insignificant 23 Gbps, up less than 10 Gbps from the December 2009 requirement (14.6 Gbps) – which is why users ought to be demanding better value in their mobile broadband plans.

So what does all this mean? Most of all, The Register would suggest, it reflects a user base becoming more savvy about what they do with their wireless toys.

The very cheapest way to suck data into the smartphone or fondleslab is to grab a WiFi network whenever it’s available (most often, at home), and use the expensive mobile network as required rather than by default.

That near-tripling of fixed broadband growth isn’t, it would seem, just an explosion of video piracy: it’s also the multiplication of devices in the home, and the way that devices like tablets change user behaviour. Instead of a delineation between “using a computer” and “doing something else”, the tablets and smartphones are convenient anywhere; they sit on our laps while we watch TV, and they come to the bedroom with us.

Users are downloading lots of stuff to the smartphones and tablets, and they’re doing it more constantly and in more places. They’re just too smart to pay over-the-odds for the data we download, when the home and the office have WiFi available. ®