[Complete] Scheduled World Alliance Maintenance - June 9, 2015

Physical world mergers is more akin to a database merge, or possibly a physical server merge or both, and hence the temporary expanded (but one-use) storage limit. There is probably a physical/virtual data size or entry limit that makes them prevent you from creating more characters once you hit that limit.

World Alliances conceptually seem more like a database share, or simply connecting several servers together as a bundle (but still with their individual addresses). Resource-wise physical world mergers take a great deal of manpower time, whereas world alliances probably need the least effort and also creates the least disruption.

Hadriel