I would view this as Laplace smoothing or Additive smoothing for binary distributions (https://en.wikipedia.org/wiki/Additive_smoothing https://en.wikipedia.org

I would view this as Laplace smoothing or Additive smoothing for binary distributions (https://en.wikipedia.org/wiki/Additive_smoothing https://en.wikipedia.org/wiki/Additive_smoothing). I use it all the time when I'm working estimating rates of some events from a limited amount of samples.