Not realizing that this topic had be started three days prior, I posted this:
https://bitsharestalk.org/index.php?topic=2887.0 about coffee.
If the quantity of BitStuff were a small fraction of the amount of ActualStuff in the world, then BitStuff could
appear to be backed by inventory in the possession of low-cost producers.
The price that one observes is the value of the most recent transaction that splits the market between bears (pessimists) and bulls (optimists). Among suppliers in a competitive market will be those at the one extreme whose production costs are greater than the prevailing price, who are priced out of the market, and those at the other extreme whose production costs are less than the prevailing price, who are making tidy profits.
If, for example, a low-cost supplier of ActualStuff sold to a local monopsony (one-buyer) market, as is the case in much of the Developing World, then that supplier might be able to deal directly with holders of BitStuff. Although there were no contractual obligation to back BitStuff with ActualStuff, it might
feel to a casual observer as if it were.