People use each other quite a bit in Rosencrantz and Guildenstern are Dead, and part of the reason the main characters, Ros and Guil, are never in control of their situation is because they seem naively incapable of using the people around them. Manipulation, in many ways, is compared the act of directing a play – it's the ability to control the course of events. A play is explored as something that manipulates the audience: something that attempts to affect the way that they think and feel.
Ros and Guil are too oblivious to be able to manipulate anyone. Their fate arises because they are manipulated by both Hamlet and Claudius, but for different and conflicting purposes.