1. A method, comprising: storing, in a computing apparatus, transcripts of communications over communication connections established by a connection server between second users and selected ones of first users, wherein; the connection server is coupled with a data store to establish real time communication connections between telephonic devices; the data store storing: communication references of a first set of telephonic devices registered in the data store, and information about the first users of the first set of telephonic devices; wherein in response to requests received from the second users of a second set of telephonic devices identifying the selected ones of the first users, the connection server establishes the communication connections between respective telephonic devices of the second users and respective telephonic devices of the selected ones of the first users using communication references in the data store; storing, in the data store, communication records of the communication connections established by the connection server; performing, by the computing apparatus, natural language processing on the transcripts to generate input vectors; generating, by the computing apparatus, ranking scores of the second users from the communication records, wherein the input vectors are correlated with the ranking scores to establish a predictive model of ranking score; and after the connection server provides a communication connection between a telephonic device of a user and a telephonic device of a selected ones of the first users: storing, in the computing apparatus, a transcript of a communication between the user and the selected ones of the first users; performing, by the computing apparatus, natural language processing on the transcript of the communication to generate first input vectors; and applying, by the computing apparatus, the first input vectors in the predictive model of ranking score to generate a ranking score of the user.