Other technologies used in advertising
Googles advertising systems may use other technologies, including Flash and HTML5, for functions like display of interactive ad formats. We may use theIP address, for example, to identify your general location. We may also select advertising based on information about your computer or device, such as your device model, browser type, or sensors in your device like the accelerometer.
Location
Googles ad products may receive or infer information about your location from a variety of sources. For example, we may use the IP address to identify your general location; we may receive precise location from your mobile device; we may infer your location from your search queries; and websites or apps that you use may send information about your location to us. Google uses location information in our ads products to infer demographic information, to improve the relevance of the ads you see, to measure ad performance and to report aggregate statistics to advertisers.
Advertising identifiers for mobile apps
To serve ads in services where cookie technology may not be available (for example, in mobile applications), we may use technologies that perform similar functions to cookies. Sometimes Google links the identifier used for advertising on mobile applications to an advertising cookie on the same device in order to coordinate ads across your mobile apps and mobile browser. This can happen, for example, when you see an ad within an app that launches a web page in your mobile browser. This also helps us improve the reports we give to our advertisers on the effectiveness of their campaigns.
To opt out of personalized ads in apps on your mobile device, follow the instructions below.
Android
1. Find Google Settings in one of these places (depending on your device):
a. A separate app calledGoogle Settings
b. In your mainSettingsapp, scroll down and tapGoogle
2. TapAds
3. Switch onOpt out of interest-based ads
iOS
Devices with iOS use Apples Advertising Identifier. To learn more about your choices for use of this identifier, visit theSettingsapp on your device.
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 current or past location. Your 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, or a search for pizza might return results for pizza places in your town.
Sometimes the ad you see is based on the context of a page. If youre looking at a page of gardening tips, you might see ads for gardening equipment.
Sometimes you might also see an ad on the web thats based on your app activity or activity on Google services; an in-app ad thats based on your web activity; or an ad based on your activity on another device.
Sometimes the ad you see on a page is served by Google but selected by another company. For example, you might have registered with a newspaper website. From information youve given the newspaper, it can make decisions about which ads to show you, and it can use Googles ad serving products to deliver those ads.
You may also see ads on Google products and services, including Search, Gmail, and YouTube, based on information, such as your email address, that you provided to advertisers and the advertisers then shared with Google.
Why am I seeing ads by Google for products Ive viewed?
You may see ads for products you previously viewed. Lets suppose you visit a website that sells golf clubs, but you dont buy those clubs on your first visit. The website owner might want to encourage you to return and complete your purchase. Google offers services that let website operators target their ads to people who visited their pages.
For this to work, Google either reads a cookie thats already in your browser or places a cookie in your browser when you visit the golfing site (assuming your browser lets this happen).
When you visit another site that works with Google, which may have nothing to do with golfing, you might see an ad for those golf clubs. Thats because your browser sends Google the same cookie. In turn, we may use that cookie to serve you an ad that could encourage you to buy those golf clubs.
Your visit to the golfing site may also be used by Google to show you personalized ads when you later search for golf clubs on Google.
We do have restrictions on this type of ad. For example, we prohibit advertisers from selecting an audience based on sensitive information, such as health information or religious beliefs.
Learn more aboutGoogle ads.

