I expect that a lot of the value of bitcoin may actually be derived from its use in darknet marketplaces.
The administrator of Silk Road was arrested on 1 October 2013, when the price of Bitcoin was $US133. By 29 November 2013 the price was $US1132. This can be explained by the masses of media attention which was received for Bitcoin over this time, however the bulk of this was in relation to Silk Road. If people learned about Bitcoin by it's association with drug markets and the price grew exponentially, it's reasonable to assume that at least a portion of this growth was due to people looking to buy bitcoin so that they too could participate in illegal markets.

If drug deals were being paid for with Jelly Beans, and after the media covered the story the price of Jelly Beans exploded, it's pretty safe to assume that a portion of people are buying them with the view to buy drugs.