Marketing ideas have their moments. About a dozen years ago, law firms discovered that by trolling electronic databases they could quickly learn when a client—or a potential client—had been sued. From there it was a short leap to firing off a note advising of the filing.

For a brief time that proved to be a novel and therefore dandy sales tactic. But soon enough, every marketing manager with a PACER account and a smartphone got into the act, and general counsel were inundated with bad—and worse, old—news about their litigation dockets. Though most clients have long since stopped biting on this bait, firms continue, as F. Scott Fitzgerald wrote in a somewhat different context, to beat on, boats against the current, borne back ceaselessly into the past.