Analytic Index provides sales share estimates for each department and its categories. These estimates are based on a number of factors including retailer reported item sales rank data of the top sold products in each category, machine learning models trained from actual sales data (note that clients are not required to contribute any data to train models as this is purely an opt-in training set from strategic client partners), and external industry data sources. Analytic Index uses all of this data and trains algorithms to create our sales share estimates in the form of market share percentages for each category. When multiple categories are summed, total share estimates are weighted according to relative category depth. Share of sales estimates can not be aggregated across different departments at this time.