What determines the ads by Google that I see?
Many decisions are made to determine which ad you see.Sometimes the ad you see is based on your location. 1. Locational BaseYour IP address is usually a good indication of your approximate location. So you might see an ad on the homepage of YouTube.com that promotes a forthcoming movie in your country.2. Trace browsing preferenceCookies are widely used by websites and servers to provide many of the basic services we find online. If you shop on a website, a cookie allows the website to remember which items you’ve added to your virtual shopping cart. If you set preferences on a website, a cookie allows the website to remember your preferences the next time you visit. Or if you sign into a website, the website might use a cookie to recognize your browser later on, so that you don’t have to sign in again. Cookies also allow websites to collect data about user activity, such as how many unique visitors a page receives per month. All these applications depend on the information stored in cookies.For instance, Remarketing/ Internet-based ads is a cookie marketing:I) How Google infers interest and demographic categories? As users browse our partner websites, Google stores an advertising cookie in a user's browser to understand the types of pages that user is visiting. This information is used to show ads that might appeal to your users based on their inferred interest and demographic categories.For example, if a user browses many sports-related websites displaying AdSense ads or watches sports-related videos on YouTube, Google may associate a sports interest category with their cookie and show the user more sports-related ads. Similarly, if the sites that a user visits have a majority of female visitors (based on aggregated survey data on site visitation), we may associate the user’s cookie with the "female" demographic category. We may also use demographics from Google profiles.In sum, remarketing make use of visitors' 1. Demographic (female/ male), 2. Interest (Sports/ Entertainment/ Travel) and 3. browsing history to publish Internet-based ad.2. Placement Ad VS RemarketingAdvertisers use placement targeting to display ads on specific sites and pages in the AdSense network. Placement-targeted ads reach users visiting specific sites, independent of their interests or demographics.Interest-based advertising, on the other hand, reaches users based on the sites they've browsed and the interest and demographic categories associated with them. Interest-based ads are shown to users based on their inferred interests and demographics, rather than the content of a specific site or page.For example, an advertiser selling footballs could reach customers through both types of advertising. They could use placement-targeted advertising to display their ads on specific football-related sites, and interest-based advertising to display ads to users in the sports interest category on sites without content specific to football.