Accounting Methodologies
I would suspect that all of them would be using activity based accounting methodologies as it is considered the better option for cost accounting. In each instance, it is a better understanding of how the money flows within the organization if cost accounting through activity is used. The difference in numbers would be that there would be less overhead in an e-business than a IT business, for example (if a few concerns were the same..IE. number of employees, size of business, etc).