how much data in that bundle?

I saw an interesting mobile services bundle advertised yesterday. It includes voice, videotelephony, texts, MMS and downloads.

On the face of it, nothing particularly unusual, except the very heavy bias towards data services, especially texts, and to a lesser degree downloads.

What I want to know is exactly how the accountants and management work out the value of each element. Is it based on that element's included allocation in the bundle? Is it based on the actual usage of those allocations? And exactly how do you work out the relative implicit value of say, actually using 800 texts vs £7 of downloads vs. all 150 voice minutes?

This advert & bundle has reminded me of a question I first thought of a couple of years back.

How exactly do carriers work out the % ARPU attributable to data services, when most of those services come pre-bundled at a non-specified cost per message/download/video minute in a plan? Is there any consistency between mobile operators? Are these numbers audited, and if so, to what rules? Do the rules vary by country, or change over time?

I'm not getting at 3 specifically here; this applies to all operators in a similar fashion. Maybe everyone shouldn't be so surprised that mobile data ARPU percentages keep creeping up, as they're such an important and closely-watched metric.... and (perhaps) so easy to "fiddle".....