Gold is fine, but you can’t order from Amazon with a gold coin. Bitcoin will be the preferred medium of exchange within 5 years. . And every entity that deals in “money” will adapt or die. Period.
Why not? Strictly speaking, you can't order from Amazon with paper dollar bills either can you? Buying over the web usually requires a intermediary payment processor of some kind. The accounts can be denominated in gold as easily as anything else. All that is needed (beyond the abatement of legal impediments) is a price structure.