In the case of Naver and N Shopping, if you match “keywords” with keyword advertisements exposed as search results, and “URL” of products posted in shopping, respectively, and save them in the NPRO app, the search rankings are periodically checked and recorded, and the rankings are reached or reached. Sends an alert to the app when leaving. In the case of Coupang shopping mall, if you register in this app by matching "product name" and "product URL", the product ranking in the search results is checked and an alarm is sent to the app.