Build a browser extension that converts a shopper's requirements into strict searches across supported retailers, separates exact matches from accessories and substitutes, and saves candidates in a persistent comparison list. The first version should support manual product capture and structured comparison before attempting broad retailer integrations. Revenue could come from a paid household subscription, with clearly disclosed affiliate income as secondary revenue.

Retail marketplaces are inserting generative interfaces and promotional results into basic search, while shoppers are explicitly asking for direct, controllable results. A lightweight independent search layer can restore that control without operating another marketplace.