The cannabis black market will control 71 per cent of sales in Canada this year, Scotiabank says Lack of consistent supply in legal cannabis shops has been a major market stimulator for the illicit sector Oliver Rowe and Ben Isaacson calculated the figure, which reduced its legal recreational sales prediction to about 30 percent, citing supply issues, government inspections, packaging snags and quality control issues as some of the reasons for the low percentage.MJ_Prototype / iStock / Getty Images Plus Emma Spears