  We study non-degenerate Reeb flows arising from perfect contact forms, i.e.,
the forms with vanishing contact homology differential. In particular, we
obtain upper bounds on the number of simple closed Reeb orbits for such forms
on a variety of contact manifolds and certain action-index resonance relations
for the standard contact sphere. Using these results, we reprove a theorem due
to Bourgeois, Cieliebak and Ekholm characterizing perfect Reeb flows on the
standard contact three-sphere as non-degenerate Reeb flows with exactly two
simple closed orbits.
