1. A computer-implemented system for prospecting digital information through online social communities, comprising: a computer comprising a processor and memory within which code for execution by the processor is stored, comprising: an information storage module configured to maintain a home evergreen index for a home community and a plurality of frontier evergreen indexes for respective frontier communities, the home evergreen index and the frontier evergreen indexes covering topically-limited subject areas, each of the subject areas comprising electronically-stored digital information, the home evergreen index and each frontier evergreen index comprising: a hierarchy of stored topics; and a stored topic model matched to each of the topics in the topic hierarchy, each of the topic models comprising a pattern evaluable against the digital information, wherein the pattern identifies such digital information matching the topic model's topic; a frontier candidate identifier module configured to identify at least one frontier evergreen index that comprises stored topics that are at least partially distinct from the stored topics comprised in the home evergreen index; a frontier candidate evaluation module configured to obtain vetted assessments as provided by the frontier community of the at least one frontier evergreen index for articles of the digital information identified by the patterns that comprise the topic models of the at least one frontier evergreen index; a frontier integration module configured to select the articles of the digital information corresponding to the vetted assessments that are favorable and to match the patterns that comprise the topic models of the home evergreen index against the selected articles of the digital information; and a display module configured to provide the selected articles of the digital information that were matched.