I think the problem with shipped figures is that they can represent faulty replacement units and retailer demo units, so it's not as useful in discerning software attachment rates. Also the manufacturer's don't issue PR statements every week detailing the latest shipped figures so an 'overlaying pillar' would be exceeded over time.
I do however, think it would be great to have continuously updated links (with dates) underneath the charts redirecting to the latest shipped PR statements from each of the manufacturer's though.







