Ads Preferences

Interest-based advertising: How it works

Many websites, such as news sites and blogs, use Google's AdSense program to show ads on their sites. It's our goal to make these ads as relevant as possible for you. While we often show you ads based on the content of the page you are viewing, we also developed new technology that shows some ads based on interest categories that you might find useful.

The following example explains this new technology step by step:

Meet Mary

Mary's favorite hobby is gardening. With Google's interest-based advertising technology, Mary will see more relevant gardening ads because she visits many gardening websites. Here's how that works:

1. When Mary visits websites that display ads provided by Google's AdSense program, Google stores a number in her browser (using a "cookie") to remember her visits. That number could look like this: 114411.
2. Because many of the websites that Mary visits are related to gardening, Google puts her number (114411) in the "gardening enthusiast" interest category.
3. As a result, Google will show more gardening ads to Mary (based on her browser) as she browses websites that use AdSense.

No personal information

Throughout this process, Google does not know Mary's name or any other personal information about her. Google simply recognizes the number stored in Mary's browser, sees that it falls into the gardening enthusiast interest category and shows more gardening ads. Google will also not use sensitive interest categories, such as those based on race, religion, sexual orientation, health, or sensitive financial categories.

Editing interests with the Ads Preferences Manager

Google also lets Mary edit the interest categories associated with her browser's number. In addition to gardening, Mary also likes to play golf so she adds this interest using Google's Ads Preferences Manager. Now she will also see more ads about golf.

Interest-based ads on YouTube

YouTube also uses interest-based advertising to show relevant ads on its site. If Mary watches many videos about cooking on YouTube, she may see more ads related to cooking as she browses YouTube and websites that use AdSense. Similarly, she may see more gardening ads on YouTube based on sites she previously visited. Because YouTube is integrated into the Ads Preferences Manager, Mary can edit the interest categories that are relevant to her in one place. To learn more about YouTube's approach, see YouTube Advertising and You.

Using a different computer or clearing the browser's cookies

Anytime Mary uses a different browser or computer, her number won't carry over because it is specific to the browser she used before. When Mary clears her browser's cookies, the number is deleted and Google no longer knows that a user of that browser may be interested in gardening and golf.

Opting out

If you prefer not to receive this type of interest-based advertising, you can always opt out by clicking the "Opt out" button on the homepage of the Ads Preferences Manager. After you opt out, Google will not collect interest category information and you will not receive interest-based ads. You will see the same number of ads as before, but they may not be as relevant.

For more information, check the Frequently Asked Questions and visit the Advertising and Privacy page of our Privacy Center.