Demographic bidding is a way to help your ad reach audiences of a certain age or gender. If you want your ads to be seen by women aged 18-24, or people over 55, demographic bidding can help.
Some publishers on the Google Content Network know certain individual details about their users. Social networking sites, for instance, often ask users to identify themselves by age and gender. On sites that provide this type of information about their users, Google can often display your AdWords ads to members of the groups that you prefer, or prevent your ads from displaying to members of groups you don't want to reach. You can bid more for your preferred demographic groups to help make sure your ad reaches members of those groups.
Demographic bidding is available for campaigns with keywords, placements, or both. It's also important to remember that some Google Content Network sites offer demographic bidding, but many don't. (Many sites that show AdWords ads don't have detailed insights into user age or other information about their users.) Your campaign is likely to have a mix of sites that do and do not offer demographic bidding.
To begin adjusting your bids based on user age and gender, please follow these steps
You may also like to learn more about keeping your ad from showing to certain users or selecting sites by demographics.
