An e-commerce price index is constructed and maintained based on consumer actions in connection with one or more e-commerce websites. A data collector software module collects information regarding products sold or available for sale online, including a price and rate of clicks received for each product on the website(s). An index software module analyzes the collected information to construct the price index. Specifically, the index software module scrubs the collected information to remove outliers and fill in gaps and calculates a click-weighted average price by product category and day. The index module generates the price index by aggregating and normalizing the calculated click-weighted average prices. The index software module can compute the e-commerce price index on a virtually real-time basis. Thus, the e-commerce price index can provide useful information about online pricing trends far earlier than traditional indices.