I would make a reference to Bitcoin's value as equivalent to a precious metal like gold or silver as an analogy due to the fact not many people know what Bitcoin is.
This post is correct. People know about Bitcoin, but it is currently no mainstream. Because of this fact, you have to compare it to gold or silver, since those can buy some* things, but not necessarily a lot of things. Bitcoin is the same way. It's not commonly used, but it can be used to be purchased different commodities or goods, or nearly anything there's a market for.
It would be like a primitive society, however, if you decided that Bitcoin would be permanently compared to precious metals, as it would be reminiscent of the times when precious metal coins were used as currency.
*I have no idea where you can buy stuff with gold or silver, but I'm sure it exists somewhere.