Fig. 3

Quarterly Amazon net sales (North America segment) and total user sample spend. Top: Data shown for total spend for the entire sample (N = 5,014). Bottom: Data shown for total spend for the stratified sample (N = 1,326). Data are correlated with Pearson’s r = 0.978 and r = 0.973 (p < 0.001), for top and bottom, respectively.