However I notice something that I think could be used to improve XenForo social media integration.
That is, I haven't seen a Facebook intergration which let user to subscribe to threads (like the normal subscribe with email) with Facebook notification. So if there is a new reply to a thread user have subscribed, they will be notified from Facebook's notification.
Since Facebook has a huge userbase, I think such a feature will be neat. So any time there is an activity within the forum board, the user will know if they're accessing Facebook (if they integrated their forum account with Facebook, that is). I think nowadays people are accessing Facebook more often than e-mail, thus rendering e-mail (as a method of notification) less effective than Facebook.
I think, using Facebook API, such a feature theoretically possible to be made. With countries that have a huge demographic of Facebook user (like in Asia), this feature I see could be a massive boost to XenForo userbase. How do you think?