From Techliberation/Bernstein::

Today, the average voice-only customer consumes something like 50 megabytes of data every month. For that, they pay about $40, or about $0.80 per megabyte. That’s 70% of wireless industry revenues. Text messaging generates another $10 per month for a minuscule amount of data (in fact, arguably no throughput at all, since text messaging travels in a signaling band rather than in the carrier band itself). Let’s call it $1,000 per megabyte. That’s another 15% of industry revenues. On a blended basis, then, that’s $1.00 per megabyte for 85% of industry revenues.

And then there’s the iPhone. By some estimates, the average iPhone user consumes as much as 800 megabytes per month. Take out their 50 Mb for voice and you’re looking at 750 Mb of data… for an additional $30. For the mathematically challenged, that’s a princely sum of… wait for it… four cents per megabyte. Worse, we noted that the FCC’s wireless net neutrality policies posed the risk of “bandwidth arbitrage,” where low bandwidth services (at $1.00 per megabyte) would be replaced with free or almost free applications that ride on $0.04 per megabyte data plans, and where carriers’ hands would be tied to prevent it. Taking a business that is currently getting $1.00 per megabyte down to just $0.04 per megabyte is, well, hard.

From CTIA:

According to the FCC’s most recent data, there were over 59 million mobile wireless high speed lines.

In addition, mobile wireless broadband growth continues to outpace every other broadband platform, with net additions between December 2007 and June 2008 greater than those of DSL and cable modem combined.

Mobile data and Internet traffic will increase 66 times between 2008 and 2013;

By 2010, “mobile broadband penetration will surpass fixed penetration globally.”

The simple task of watching a YouTube video consumes 100 times the bandwidth of a voice call.

The mobile data traffic footprint of a single mobile subscriber in 2015 could very well be 450 times what it was in 2005.

From: http://techliberation.com/2009/11/21/the-wireless-bandwidth-crunch-where-will-we-find-more-spectrum/