Cannabidiol-based products are attractive to consumers because of their wide range of potential health effects. Despite the hype of this market, there is a substantial lack of information on consumers' attitudes and motivations toward light cannabis products. We thus conducted an ad-hoc online survey to investigate the characteristics of French and Italian users, focusing on smoking as the main mode of consumption. Logistic regressions are performed to explain the factors associated to light cannabis use as a substitution for any drug or for a specific substance. Our results indicate that one out of five current light cannabis users use it as a substitute (self-replacement therapy) for other substances. The reduction in substance use is more prevalent for regular cannabis, tobacco and medications than for alcohol use. However, the use of light cannabis seems to facilitate alcohol consumption reduction, mostly among males with low income. Whereas sublingual oils are more likely to be used to substitute medications, smoking is the favourite means of substitution for tobacco and regular cannabis. Overall, the motivations behind consumption determine differential preferences across light cannabis users. This calls for a rethinking of the most adequate distribution channels for specific products based on the purpose of use. The goal should be to maximize the substitution with other addictive substances by providing a differential degree of quality and taxation across supply channels based on the expected harm.