Google allows companies to target you based on your email address

Google announced the roll out of a new advertising tool recently on the company's official Adwords blog that allows companies to target users based on email addresses.

The system, called Customer Match, works in the following way. Companies upload email addresses they want to target to Google, for instance by uploading emails of part of the company's customer base to Google.

Companies get new capabilities then to target these users on Google properties provided that users are logged into their Google account at the time.

Google states that the matching happens in a "safe and privacy-safe way" but does not provide additional details as to what that means. It most likely means that company's cannot use Customer Match to target or track individual users but only the group of users.

The example given by Google has a travel brand target users who joined the company's reward program on Google Search when they search for flights and to show ads to them on Gmail or YouTube that may inspire them to plan their next trip.

Customer Match lets companies target new customer through its Similar Audiences feature on YouTube and Gmail. Google will show these ads to non-customers who match certain characteristics and interests as existing customers (based on the list of email addresses uploaded to Google).

Google is not the only company that's letting advertisers target users by email address. Facebook and Twitter do the same, but they are limited to a single product while Google offers the new advertising program across different platforms.

Privacy advocates may have a couple of issues with this new advertising form. Probably the biggest one is the uploading of emails to Google. Customers who buy products or services from company's may not be too happy to learn that the company has uploaded their email address to a third party (Google) without their consent.

There is also the question whether their is a lower limit of email addresses that company's can upload to lists they create. If not, what is keeping them from creating individual lists for one or a handful of email addresses to target individual users this way.

What you can do about it

Google notes that customers can opt-out of personalized ads in the Google Ads Settings. All that needs to be done on the page is to switch the "ads based on your interests" preference to off.

Other options that you have at your disposal are to make sure you are signed out of your Google account whenever you using Google products. That works only for some products however, as you cannot use Gmail on the web at all if you are not signed in to your account.

Now You: Tell us what you think of Google's Customer Match advertising format.