Conclusion Citation counts can be reliably predicted at two years using data within three weeks of publication.

PIRUS — Publisher and Institutional Repository Usage Statistics: Final Report, report, January 2009. (Thanks to Charles Bailey.) From the executive summary: The aim of PIRUS (Publisher and Institutional Repository Usage Statistics) was to develop COUNTER-compliant standards and usage reports at the individual article level that can be implemented by any entity (publisher, aggregator, repository, etc.,) that hosts online journal articles and will enable the usage of research outputs to be recorded, reported and consolidated at a global level in a standard way. ...

Conclusions : Impact factor may be a reasonable indicator of quality for general medical journals.

Evaluating scientific quality is a notoriously difficult problem which has no standard solution. Ideally, published scientific results should be scrutinised by true experts in the field and given scores for quality and quantity according to established rules. In practice, however, what is called peer review is usually performed by committees with general competence rather than with the specialist's insight that is needed to assess primary research data. Committees tend, therefore, to resort to secondary criteria like crude publication counts, journal prestige, the reputation of authors and institutions, and estimated importance and relevance of the research field,1 making peer review as much of a lottery as of a rational process.2 3