Badges is a good way to reward members and to keep them motivated. But that moment of getting a new badge is also a happy moment which, I think would be worth sharing within their social circle. Can that sharing process be made much easy and obvious by showing social share icons beneath every badge (with a small message to share it with their loved ones)? I have also seen something same on CodeCademy badges.
Moreover, it also generates a lot of social activity for the website which is always best.