GWTW,

Here's One More Factoid to Consider When Figuring How Many Explorers Eventually Become Mines:

This from page 2 of http://www.caseyresearch.com/pdfs/20090820_0908208PsPROOFED.pdf

"...between 95% and 99% of all the properties controlled by mining companies will never actually become mines. That’s because finding a mineral deposit with the potential to host an economic resource is time consuming and expensive. And unlocking the economic value of the embedded minerals is even more so. The cost of building a mine and a mill starts at a minimum of $50 million these days, and can climb to a billion or more."

B.