How Ads Work

At a glance, you make ad spaces (also known as ad inventory) available on your site. Advertisers bid to show their ads on your site and the highest bid wins. You get paid when users click on the ads.

This guide covers the basics of how ads work, but to learn more, refer to the Google AdSense and Google DoubleClick help centers.


  • Choose the ads platform best suited to your site. We recommend the AdSense platform for most sites, and the DoubleClick platform for sites with their own advertising teams.
  • Ads work best when they integrate nicely in your site; their color, content, size, and location enhance user experience.
  • Users click on ads that are relevant to the content they are looking for; understand how ads targeting works so that you can maximize your revenue.

Choose the best ads platform for your site

There are many ad serving platforms available, and choosing the one that is right for you is important. We recommend the Google AdSense platform for most sites; it’s free use and available to almost any site. The DoubleClick platform is best for sites with their own advertising teams.


Google AdSense is a free, simple way for sites of all sizes to earn money by displaying targeted ads. AdSense shows ads that are relevant to your users with automatic targeting. You do not need to manage inventory or advertiser relationships, AdSense gives you instant and automatic access to a huge source of advertiser demand.

AdSense also provides you with the tools you need to be successful, including:

In addition, AdSense provides the ability to choose from a variety of ad sizes and formats, including responsive ads that serve the right sized ad for responsive sites.

DoubleClick for Publishers

DoubleClick for Publishers is an ad management platform that helps sites sell, schedule, deliver, and measure all of their ad inventory. Sites can reserve some, or all of their inventory for ads from their own dedicated advertising sales teams or auction-based services like AdSense or AdExchange.

Get the most from your ads

Ad placement

Place ads where they are visible, but don’t detract from the main user experience.

Common examples of where to place mobile ads

For example, 320×100px ads may be interspersed through list content, articles may include a 300×250px ads, and long form content may include a combination of ads. Refer to Best practices for ad placement in the AdSense help for further details.

Ad size

For the most flexibility, use responsive ads. Responsive ads are automatically sized based on the user’s device.

Sample website with ads on desktop and mobile

It may be necessary to use statically sized ads, in this case, refer to the Guide to ad sizes.

Ad type

To maximize the ad inventory available to you, be sure to choose both text and display ads.

Ad style

In many cases, you have control over the color, font, and font-sizing for text ads. Choose styles that match or contrast the styles on your site.

For example, you can change the color of URL text so that users see clearly where the link will take them.

How ads are targeted

Google AdSense automatically delivers ads that are targeted to your content or audience. This is done in several ways:

  • Content and language - users will see ads that match your site’s content and language.
  • Placement - advertisers can target sites that have ad units placed where they want their ads to appear, and matched to the size they want their ads to be displayed in on targeted devices.
  • User’s interest - your website and advertisers can target specific user groups, for example, sports enthusiasts.

How ads are selected

The ad auction is used to select the ads that will appear on your pages and determine how much you’ll earn from those ads. In a traditional auction, interested bidders state the maximum price they’re willing to pay to buy a specific item. Similarly, our ad auction allows advertisers to state the price they’re willing to pay for clicks on ads or for impressions served on AdSense pages.

Updated on 2014-07-31


Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies.