Weak value amplification (WVA) is a concept that has been extensively used in
a myriad of applications with the aim of rendering measurable tiny changes of a
variable of interest. In spite of this, there is still an on-going debate about
its true nature and whether is really needed for achieving high sensitivity.
Here we aim at solving the puzzle, using some basic concepts from quantum
estimation theory, highlighting what the use of the WVA concept can offer and
what it can not. While WVA cannot be used to go beyond some fundamental
sensitivity limits that arise from considering the full nature of the quantum
states, WVA can notwithstanding enhance the sensitivity of real detection
schemes that are limited by many other things apart from the quantum nature of
the states involved, i.e. technical noise. Importantly, it can do that in a
straightforward and easily accessible manner.Comment: 2 pages, 5 figure
