A playerette is like a player but with an extra step in her motivation chain. After all, guys are pretty straightforward: we want sex. Playerettes, on the other hand, use sex as a means to an end, a tool to get things like favors, money, dinner...
A playerette will always have five or six guys around her, as she will use each of them for something different. For example, Carl will pay her rent, Paul, her phone bills, Pat, her car lease, until finally, she's only having sex with one of them... hopefully you.
Remember that a playerette will always get sex in the end -- either from you or someone else.
Since it can be difficult, even for The Player, to imagine his traits in a woman, here's a paradigm: a good example of a playerette is a stripper. Although not all strippers are playerettes, and certainly not vice versa, I choose a stripper because, when you get right down to it (something many guys never end up doing with strippers), she uses sex to get money from men. But when customers stop paying for her "services," she drops them.