Maybe someone more knowledgeable than me can inform their users of why DRK > BTC I think a lot of them would be interested in learning more about DRK, many take OPSEC very seriously. The forums are separate from the merchant sites but you still need TOR browser to connect.
It seems some of the Silk Road users are just putting their coins on an exchange, buying DRK to then anonymize, then buying back BTC.