You could limit it to just the energy usage of the product in its stated purpose, or you could even add in the carbon output needed to manufacture it.

FORBES: Was Reagan Right About the Energy Department? Solyndra Case Study

Intel is going to make its own graphics product out of its general-purpose processors, and amd will seek to fold sophisticated graphics capabilities into its CPUs, stealing business that would otherwise have gone Huang's way.

FORBES: Magazine Article

Dr. Bronner's best-selling product, a bottle of all-purpose liquid hemp peppermint Castile soap, is not your run-of-the mill cleanser.

FORBES: Magazine Article

Many people would say the purpose of managing-up is to have the by-product of your efforts enhance the work of those you report to.

FORBES: My Advice On Managing Up - Don't

The debt limit has not achieved its original purpose of limiting government spending, which rose from 9.5 percent of gross domestic product in 1917 to 18.2 percent in 2000 to 24.1 percent this year.

FORBES: Butterflies, Trains And The National Debt

And the super committee will go about its business with great seriousness and sense of purpose, will take his proposals into account, and produce a balanced, bipartisan product that Congress can then act on that represents significant deficit and debt reduction.

WHITEHOUSE: Press Briefing

All in all, this legislation is that rare end product of what happens when Americans of all parties and places come together in common purpose to consider something more than the politics of the moment.

WHITEHOUSE: President Obama Signs Major Public Lands Protections