Downloadable computer software for facilitating electronic commerce transactions; Downloadable computer software for use in shopping for secondhand or up-cycled retail goods; Downloadable computer software for use in aggregation of fashion styles; Downloadable computer software, namely, internet browser extensions, plug-ins, and applications for use with electronic commerce transactions, product price monitoring, and product pricing comparison; Downloadable computer software featuring offers, deals, coupons, rebates, rewards, vouchers, price tracking, price notifications, price-comparison information, links to the retail websites of others, promotional materials, and discount information; Downloadable computer software with an Internet browser extension which provides information relating to offers, deals, coupons, rebates, rewards, vouchers, price tracking, price notifications, price-comparison information, links to the retail websites of others, promotional materials, and discount information; Online advertising and promotional services; Promoting the sale of goods of others via a global computer network; Promoting the sale of secondhand and up-cycled goods of others by providing interactive online applications featuring offers, deals, coupons, rebates, rewards, vouchers, price tracking, price notifications, price-comparison information, links to the retail websites of others, promotional materials, and discount information; Providing incentive award programs through issuance and processing of coupons and discounts for purchasing the goods of others; Downloadable computer software using artificial intelligence for curating and recommending fashion styles based on user inputs and preferences; Providing information about sustainable fashion via a website and web based application