This week Facebook announced the global rollout of new Custom Audiences capabilities designed to target people who’ve visited a website or mobile app. Previewed in October, the feature combines the power of Facebook’s existing Custom Audiences capabilities with real-time automated audience creation.

If you’re unfamiliar with Custom Audiences, the tool lets marketers upload a list of contacts (email, Facebook UIDs, phone numbers) to the social network, which matches them with their Facebook user ID and shows them highly targeted Facebook Ads. It’s similar to the Facebook Exchange (FBX) but isn’t limited to just one type of ad. Additionally, Custom Audiences can be created through Power Editor and the Ads Create Tool, unlike FBX.

For example, you can use the emails and phone numbers of people in your customer contact list to increase Likes for your Page. You already know that the people who sign up for your email list are interested in your product or content. By creating a Custom Audience and excluding existing fans, you’re able to deliver targeted ads directly to people who want to be connected to your brand.

Sounds great, right? But that’s not all Custom Audiences can do. Let’s take a look at some of the upgrades the feature has received that make it must-have for marketers and advertisers.

Objective-Based Targeting

Right now you can create a Custom Audience representing any group of customers or prospective customers that you’d like to reach with targeted Facebook Ads. For example, you could run a campaign to get more Likes for your Page, extend the reach of your posts, sell an upgrade or new product, or target people similar to your subscribers through Lookalike Audiences (more on this one below).

But for starters, let’s focus on the latest upgrade which allows you to target people who’ve visited your website or mobile app. Here’s how it works: Place the Facebook remarketing pixel on your website or the Facebook SDK in your mobile app and use it to build Custom Audiences based upon the actions people take. From there, you can then deliver ads to those people based on their actions.

For example, a travel website could use Custom Audiences to reach people who searched for flights but never made a reservation with a targeted message in News Feed. Similarly, a retail mobile app could build retargeting campaigns around people on mobile or desktop, encouraging them to come back and purchase the items left in their shopping cart.

Offline Sales Measurement

While the ability to measure offline sales itself isn’t new, the functionality was recently extended to a wider range of businesses, all of which are now able to measure how well Facebook Ads convert offline. Greater access to Custom Audiences has given more retailers the ability to measure sales lift and analyze their campaigns directly through the social network, without having to rely on a third-party partner.

Retailers upload hashed data, including emails, phone numbers, and addresses, as well as encrypted transaction details. From there, Facebook matches your hashed data to hashed data from its database. The social network will then provide a report that compares (on an aggregate basis) the purchase behavior of customer who saw an ad on Facebook with those who didn’t.

This particular type of measurement will be especially beneficial for retailers and e-commerce sites. If you’re interested in measuring offline sales driven through your Custom Audiences campaigns and are already working wit ha Facebook client partner or account manager, you can contact your representative to learn more.

Lookalike Audiences

Launched in Spring 2013, Lookalike Audiences let you reach new people who are likely to be interested in your business because they’re similar to a customer list you already care about. It builds off Custom Audiences and uses interests or demographics to show ads to people who share common attributes as your existing customers.

Lookalike Audiences can be used for fan acquisition, site registration, off-Facebook purchases, coupon claims, and brand awareness. Facebook noted that it will only include people from the country you specify. If your Custom Audience includes people from more than one country, only the qualities of people from the specified country will be used to build the Lookalike Audience.

During testing, an online travel site reportedly saw 70 percent lower costs per action, and an online shopping site saw 94 percent lower costs per checkout. In March 2013, Facebook said Lookalike Audiences resulted in a “wide range of success metrics” for companies like Fab, including lower cost per checkout, lower cost per acquisition, larger purchase size, as well as faster and increased return on investment.

According to Facebook, thousands of advertisers, including more than half of the AdAge 100, already use Custom Audiences in their campaigns. Between Q2 and Q3 2013, there’s been an almost 75 percent increase in the number of marketers using the tool.

At this time, you can upload data for your Custom Audience using email addresses, phone numbers, Facebook user IDs, app user IDs, or IDFAs — an advertising ID that Apple provides as part of its framework. We recommend reading through the Facebook Custom Audience Terms of Service, if you already haven’t. Facebook also provides documentation on how to create a Custom Audience through the ads create tool and in Power Editor.

[Via: Inside Facebook, Image credit: Timm Suess, Mark Walz, quinn.anya, miggslives]