In "The Crucible", why do Tituba, Abigail and Betty name certain people who they claim accompanied the devil?

In the beginning of the play, Tituba, Abigail Adams, and Betty all name Sarah Good and Goody Osburn as being associated with the devil. They do so, first and foremost for self preservation. Secondly, they specifically named Sarah Good and Goody Osburn for one main reason: they both had poor reputations amongst the town of Salem. An outcast and an alcoholic, respectively, are named by these three young females because it would not be regarded as unbelievable if these two women were accompanied by the devil. However, Abigail and Betty eventually begin to name certain people only for their own benefit. This, in reality not in the play, leads to Abigail's ultimate demise because she eventually names the wife of a high up judge which leads her to flee.