Using keywords that are not closely related to the ads in their ad group can decrease the likelihood of your ads being clicked, which can lower your ads’ quality index

Remember, both an ad's quality (its historical and expected performance) and bid amount are considered in determining an ad’s position in search results.

Keywords should be grouped in the same ad group only if they are closely related and it makes sense for them to use the same ad copy. Grouping keywords into relevant ad groups also makes it easier to:

• Craft ads that are more specific and relevant to your keywords.
• Test different landing pages—and potentially increase conversion rates.

For example, if you sell electronic products, you may want to place keywords related to “camera”, “video games” and “DVD players” into separate ad groups. This enables you to write ad that are specific to those items. You may also consider grouping individual or smaller groups of similar keywords into an ad group to get a better read on your ads’ quality index.

Learn more about creating a new ad group, or how to add and delete keywords.