The main strength of this show is not character progression or depth, but variation on a strong formula that is present in each episode. An individualistic problem, such as a character flaw or personal crisis of a stranger puts the main character Moguro Fukuzou, in position to "Fill Their empty Soul". This formula is used in nigh every episode. The type of problem and how the Stanger deals with it are the variation that keeps the show interesting from episode to episode.
Moguro Fukuzou, acts not only as the catalyst for the story, but as the main comedic relief of the show, in a very eerie creepy manner.
If your interested in watching Laughing salesman, I recommend trying out 4 random ones and if you aren't captured by anything in them then you won't like the rest of it.