Other search engines like google and yahoo associate your ad-click on habits with a profile on you, which can be utilised later on to focus on adverts to you on that search engine or all around the online market place. We wrote an entire guidebook about browsing in Korea here. https://codyxztbn.newbigblog.com/41137162/the-fact-about-busan-더오션룸-attractions-that-no-one-is-suggesting