The Church of Jesus Christ of Latter-day Saints has a pilot program where a few missionaries have a Facebook page and a blog about their missions. Only 4 missions in the whole Church have been asked to participate and this young sister's mission is one of them. Check out "Hermana Anderson" and her blog. (FYI: Family members are not allowed to "friend" missionaries on Facebook and are not allowed to make comments on missionary blogs.) Social media tools can spread the gospel message.
(This is the daughter of a dear friend we knew in Denver 25 years ago.)