Twenty-eight years, and 3.7% of them
The corpus runs from 1996 to 2023, but the first seventeen years hold 3.7% of the reviews. What looks like a long history is a short one with a long tail — and the two discontinuities inside it matter more than the trend.
Full aggregate — 507.7M reviews
6 minUpdated August 2026Composition
The first seventeen years are 3.7% of the data
1996–2012 spans 17 of the corpus’s 28 years and contributes 3.7% of its reviews. 2017–2023 contributes 72.7%. Any statistic pooled across the full history is, arithmetically, a statistic about the last decade — so “we have data back to 1996” is true and almost never load-bearing.
Reviews per year, all categories
Bars shaded by era. 2023 is partial — the corpus stops at September 14, 2023.
Explore
Volume and rating by year, one category at a time
Pick a category. The two charts below and the numbers in the prose all follow the selection.
all 33 categories peaked in 2021 at 70.1M reviews. Among years carrying at least 1% of the category, the mean rating was highest in 2016 (4.29★) and lowest in 2022 (4.03★) — a spread of 0.26 stars that has nothing to do with which products were sold.
Reviews per year — all 33 categories
2023 is a partial year and is drawn faded.
Mean rating and verified share by year — all 33 categories
Years under 500 reviews are dropped — a rate computed on a handful of reviews is noise.
Effort
A CD review is five times a gift-card review
Mean review length runs from 428 characters in CDs & Vinyl down to 83 in Gift Cards. The long end of the scale is entirely media — the categories where a review is a piece of criticism rather than a receipt.
Mean review length by category
Characters. Media categories in amber.