http://online.wsj.com/article/SB10001424127887324439804578115282233557780.html

This article is self-serving in the extreme. It is easy to say:

 I don't think Agatha Christie or Arthur Conan Doyle ever worried about this. As long as they concocted tricky plots, Hercule Poirot or Sherlock Holmes could be served up over and over with barely a fresh sprig of parsley because almost nothing in their personal lives ever changed (if one doesn't count being sent over the Reichenbach Falls).

For over 40 years, a few sentences were enough to remind readers that Poirot was a meticulous little Belgian and Holmes a quirky intellect who lived at 221B Baker Street. ... To be fair, though, readers back then didn't seem to mind. The genre was still so new that workmanlike literary skills, an eccentric protagonist and a surprise ending were enough.

Of course, Sherlock Holmes and Hercule Poirot are not such amazing creations as, " a North Carolina district court judge." At the end of the day, they are unique, Holmes certainly more than Poirot, and that is why they were popular then and that is why they are more popular now than a certain, “North Carolina district court judge." This is also why they will be popular in fifty years, when those novels of about, " a North Carolina district court judge," are pulp (or 0 and 1).