Amazon Reviews – Full Dataset contains 34,686,770 product reviews, including 6,643,669 Amazon users’ evaluations of 2,441,053 products. This dataset mainly comes from the Stanford network analysis project SNAP, where each category contains 600,000 training samples and 130,000 test samples.

This dataset was released by Cornell University in 2013, and the related paper is "Hidden factors and hidden topics: understanding rating dimensions with review text".