May 27 (Reuters) - Facebook Inc said its customers' ads would now be visible on third-party apps and websites to everyone who has ever visited its website, and not just to users logged into its social networking service.

However, people can opt out of seeing ads on apps and websites not offered by Facebook, based on their ad preferences, the company said late on Thursday.

Facebook, like other online ad service providers, uses cookies to collect data on users' browsing habits to show them relevant ads.

The company, which has more than 1.6 billion users, offers online advertising services under its "Audience Network" business.

In the first quarter, Facebook generated more than 80 percent of its $5.20 billion ad revenue from mobile ads.

The company has been rolling out new features to ramp up mobile advertising and to encourage customers to experiment with video advertising.

(Reporting by Rishika Sadam in Bengaluru; Editing by Kirti Pandey) ((Rishika.S@thomsonreuters.com;)(within U.S. +1 646 223 8780, outside U.S. +91 80 6749 6997)(; Reuters Messaging:)(Reuters Messaging: rishika.s.thomsonreuters.com@reuters.net))