He offers some free samples. Probably random of course, but I believe the idea of the free sample is to get the target hooked, so he can then broaden his market. That said, at least the one free sample I had, he does not sell. I think he's not doing very well at his business. The suggestion is, that he sells all the types of free samples that he offers.
Maybe if you made your persuade check.
Yeah, good suggestion. I keep getting a special brand of wine from him, which he's not selling either. It would be nice if he sold a few different kinds of narcotics, not per se limited to the current selection of free samples that he offers.
If I recall correctly I had to make some manner of check with this NPC each time which meant he showed me more of his wares each time. So not sure if this is still applicable and people are just not making checks? (think it was appraise)