Abstract In this study, we research on a company’s sport good sales forecasting on Amazon.com. We analyze data including transactions, advertisement reports, customer reviews, competitors’ prices and customer reviews, holiday-or-not, and weekend-or-not for more than 500 days. We implement machine learning models to tackle the sales forecasting problem. The main objective of this study is to discover the most efficient model among linear, LASSO, and Ridge regression by comparing their mean absolute error in the testing set. We find that the most efficient model is LASSO regression in general, whose performance may be better than linear regression by 87 % on a certain product.