Pay for your inventory.

[BreathlessTao]

http://www.siliconera.com/2015/06/17...-item-storage/

...I swear I've not heard any dev of an online game complain this much about network traffic. And yeah, complete backups of everyone's everything, every 15 second - that is plain insane. (Guess there is one major potential reason for all those disconnects.) If they fail to realise this, idek what to say - and they apparently do fail to realise this, considering how they rather outed the option to have more space for money instead of prioritising that optimisation Yoshi talks about there. On a sidenote, I really am curious just how big is that "probably biggest" save data size per character, and what on earth they do to make it so big.

[Fyce]

On a sidenote, I really am curious just how big is that "probably biggest" save data size per character, and what on earth they do to make it so big.

That point is irrelevant since they made the armory system which allows you to play every class/job on one character only.
If you keep that in mind, the amount of data regarding gear, stats, levels, etc. will obviously be bigger than any other MMORPG which doesn't have that kind of system in place (implying that people are using alts and mules).

What needs to be compared here is the amount of data per account between games, not per character. If we compare that, I'm pretty sure that a WoW account is close (ifnot bigger) than a FFXIV account.