But that can mean different things in different industries:

Software has traditionally been very cash-efficient. Now being overtaken by Web 2.0 online endeavors.

Other industries have figured out their own way of cash-efficient financial strucutre during the development stage: Biotech companies are usually acquired before productization, as the amounts neccessary for drug marketing exceed what VCs can provide; and there’s still a lot of risk involved at that stage. So much risk actually that even pharma-companies need to take a portfolio-approach for new drugs; whereas software companies are usually one-product companies.

It gets interesting – as you point out – in emerging technologies where there’s no clear financial industry structure, such as clean-tech. A lot of the manufacturing facilities were financed with venture capital, whereas in more traditional industries this would be financed through debt.

And that can only work if there’s an assumption about sustainable growth of cash flows at some point. I.e. “promise”.