Hybris Marketing and Facebook Ads - Process

Hi,

I am currently investigating the potential for a Hybris Marketing and Facebook ad integration at my client. So far things seem pretty straightforward from a technical perspective. However I am struggling to get my head around how the data side and the process...

So I understand that from Hybris Marketing, we perform segmentation on our contacts and then push this target group down to Facebook in the form of a Campaign, however surely that means that you need to know the Facebook ID of each contact? I am not sure how an organisation would manage to get this information unless they blatantly ask the contacts for their Facebook ID. Is there something more slice that goes on instead i.e. some kind of profile stitching on the facebook side from the email address to the facebook id?

Many thanks,

Mike