Distance. The German market for cannabis would be negligible internationally and if there were to be large waves of legalization globally, I would rather bet on BAT, PMI and the like than on a small start-up.
But in general, I don't think much of the cannabis market.
@NeoInvestor The cannabis market is extremely small, even in the health sector. (Only a few people believe that cannabis is an "all-round wonder drug" and is "suppressed by the evil pharmaceutical lobby.")