  Recently, the concept of daemonic ergotropy has been introduced to quantify
the maximum energy that can be obtained from a quantum system through an
ancilla-assisted work extraction protocol based on information gain via
projective measurements [G. Francica {\it et al.}, npj Quant. Inf. {\bf 3}, 12
(2018)]. We prove that quantum correlations are not advantageous over classical
correlations if projective measurements are considered. We go beyond the
limitations of the original definition to include generalised measurements and
provide an example in which this allows for a higher daemonic ergotropy.
Moreover, we propose a see-saw algorithm to find a measurement that attains the
maximum work extraction. Finally, we provide a multipartite generalisation of
daemonic ergotropy that pinpoints the influence of multipartite quantum
correlations, and study it for multipartite entangled and classical~states.
