Over the weekend, Google announced a powerful new feature in AdWords that will allow advertisers to target their audience unlike ever before. Through Customer Match, a new feature rolling out in the coming weeks, advertisers will be able to target ads by email address.

After you upload a list of email addresses, Customer Match will pair them with the corresponding Google users who you can target ads to. Advertisers can also target ads to similar audiences who share similarities with the individuals in the email list.

Customer Match is capable of targeting ads to anyone signed-in to Google on Gmail, Search, and YouTube.

With the audience sets generated by Customer Match, you can craft ads specifically build around reaching them, such as in the example provided by Google:

“Let’s say you’re a travel brand. You can now reach people who have joined your rewards program as they plan their next trip. For example, when these rewards members search for “non-stop flights to new york” on Google.com, you can show relevant ads at the top of their search results on any device right when they’re looking to fly to New York.”

There are still no details about any security measures in place to protect customer email addresses uploaded to Customer Match, other than stating the process is conducted in a “secure and privacy-safe way.”