Facebook referrerType not marked as "social" (no replies)

Hello,
I'm new on this forums. I'd need a little help.

When I try to access Live.getVisitorProfile method in the API, I expect visits from social networks to have referrerType=social.

I see the referrerType field set to "website" instead.

http://mywebsite.com?format=JSON&module=API&token_auth=something&method=Live.getVisitorProfile&idSite=1&visitorId=7236f6fc59684272

How can I fix this so visits from social networks will be reported as "social" ?

Thank you in advance.