For more information from Facebook:
Giving you more control over ads
We've heard from some of you that it can be difficult to control the types of ads you see if you use multiple devices and browsers. In the past, if you opted out of certain kinds of advertising on your laptop, that choice may not have been applied for ads on your phone. We know that many people use more than one phone, tablet or browser to access Facebook, so it should be easy for you to make a single choice that applies across all of your devices.
That's why Facebook respects the choices you make about the ads you see, across every device. You can opt out of seeing ads on Facebook based on the apps and sites you use through the Digital Advertising Alliance. You can also opt out using controls on iOS and Android. When you tell us you don't want to see these types of ads, your decision automatically applies to every device you use to access Facebook. Also, we're now making ad preferences available in additional countries, beginning with Australia, Canada, France, Germany, Ireland and the UK.