It seems the relaunch of FFXIV is doing well, so well in fact that Square Enix had to stop selling the game due to the fact they can't keep up with server load, although I'm not sure I believe it. Adding servers to meet demand should be standard and something they should have been ready for unless someone is horrible at their job. Personally I think it's a marketing ploy to show that the game still has a strong player base and there's a demand for it. Its sort of like shipping a low amount of items then bragging about how you sold out.
Source
FINAL FANTASY XIV, The Lodestone | Announcing Server Enhancements and the Temporary Suspension of Digital Download Sales (08/28/2013)
Source
FINAL FANTASY XIV, The Lodestone | Announcing Server Enhancements and the Temporary Suspension of Digital Download Sales (08/28/2013)
