Facebook's Custom Audience ads, which allow brands to target ads to users with whom they have an established business relationship, just got more powerful now that Salesforce's Marketing Cloud can hook in.

Michael Lazerow, CMO of Marketing Cloud, announced at the Dreamforce conference in San Francisco, CA., that brands using Salesforce can reach into their pool of stored CRM email addresses—acquired over the course of a business relationship—and target messages to those customers on Facebook.

“I just bought a Ford Flex,” Lazerow says. “Ford doesn't want to spend money advertising the Fusion Hybrid to me. But they do want to market tips for new car owners and see whether I've been taken care of.”

What makes this combination so powerful and capable of hyper-targeting is the fact that brands take in a lot of email addresses. Lazerow anticipates that this feature will be tremendous for travel and e-commerce businesses. Starwood Hotels, for instance, has nine brands.

“Think what that means,” he says. “Starwood can create ads for the St. Regis people that are different than ads for the Sheraton people.”

Hyper-targeting ads also benefits Facebook which, according to its Q2 earnings report, derives 84% of its total revenue from ads. The value of Facebook ads have been steadily increasing, according to a July report from TBG Digital, thanks largely to its new mobile ads.