Understanding the 'Spice' phenomenon

Smokable herbal mixtures under the brand name ‘Spice’ are known to have been sold on the Internet and in various specialised shops since at least 2006 and anecdotal reports suggest that those products may have been available as early as 2004. Although advertised as an ‘exotic incense blend which releases a rich aroma’ and ‘not for human consumption’, when smoked, Spice products have been reported by some users to have effects similar to those of cannabis.