If you've never played Aion, here's a run-down: Socketing manastones into your gear grants considerable bonuses and is basically required for competitive PvP and PvE. Unfortunately, the random number generator that governs the process is notoriously unfriendly to players, many of whom have blown their entire in-game fortunes trying to socket a single suit of armor. Five of the new fail-proof supplements are also available as part of Aion's 24-month veteran reward package.
You can read the details on the new promotion at the official UK Aion website. NCsoft has not confirmed whether the promotion is also happening on the American servers. We'll update the post as that info becomes available.
[Thanks to Indeterminatus for the tip!]