  We characterize simply interpolating sequences (also known as onto
interpolating sequences) for complete Pick spaces. We show that a sequence is
simply interpolating if and only if it is strongly separated. This answers a
question of Agler and McCarthy. Moreover, we show that in many important
examples of complete Pick spaces, including weighted Dirichlet spaces on the
unit disc and the Drury-Arveson space in finitely many variables, simple
interpolation does not imply multiplier interpolation. In fact, in those
spaces, we construct simply interpolating sequences that generate infinite
measures, and uniformly separated sequences that are not multiplier
interpolating.
