R. Joshua b. Levi said: One who sees a friend after a lapse of thirty days says: Blessed is He who has kept us alive and preserved us and brought us to this season.* If after a lapse of twelve months he says: Blessed is He who revives the dead.**
— Babylonian Talmud, Berakhot 58b
— * “Shehecheyanu,” for short [full blessing text]
— ** Kolel: The Adult Centre for Adult Jewish Learning presents both blessings as outlined in Berakhot 58b and another option for blessing upon seeing a long-lost friend.
These blessing practice developed when correspondence was difficult and travel was so dangerous that survival was not assumed. Travel perils aside, lack of news for a year carries its own uncertainties, Rabbi Adin Steinsaltz notes. In a world where even the most far-flung individuals can stay current via electronic communications, however, it is less likely that one friend would be left wondering if the other were alive.
On the other hand, the sheer volume of electronic publishing today increases the likelihood of happening upon news of an old friend or “meeting” one via social media. Shehecheyanu is recited to celebrate a host of special moments — with emphasis on “brought us to this season,” more so than “kept us alive” — including meeting a friend after an absence. But is there a more appropriate blessing for finding a friend, after an extended lack of contact, on Facebook?
For additional consideration, here is a discussion of whether a blessing can/should be recited over a webcam “meeting.”