Emotional Prostitutes seek fulfillment through another. They find it uncomfortable or unprobable to be self fulfilled. The term has nothing to do with prostituting one's body; hence the word EMOTIONAL in front of it.
Emotional Prostitutes may seek an emotional fulfillment during sex, but it shouldn't be confused that they seek sex itself. It's the intimacy behind the sex, or the attention they receive that comes with the sexual act.
The term is a play on words, but is used to describe a common occurence within society - particularly on women because they are assumingly naturally emotional.