Isn't the statistical probability of ordering a non-drug item fairly low? This does not appear to be random. But it's still great art :)
(The numbers come from a report [1] by the Digital Citizens Alliance; the report says the count is from January 2014, but says nothing further about methodology.)
The markets that sell weapons have significantly lower proportions of drug listings, so presumably many of the non-drug listings on those markets are for weapons; much of the rest is likely exploits, credit card numbers, forgeries, etc.
0. http://www.coindesk.com/dark-markets-grow-bigger-bolder-year...
1. https://media.gractions.com/314A5A5A9ABBBBC5E3BD824CF47C46EF... [PDF]
1. https://ihb.io/2014-11-09/news/official-coindesk-longer-voic...
I imagine stealing paysites' credentials is a sort of a bike theft of the criminal web - low profit, low risk.