LOWER THE STORAGE FEE
People will leave sooner or later, because the current % is way to high and will eat through your stack like crazy. And add a feature to lock your gold and receive a lower fee that way. Me myself and many others are thinking about switching since there are other with half the fee.
Irvan Kurniawan commented
The 0.4% fee p.a. is the lowest storage fees at Pro Aurum. I think Vaultoro only get profit from the market (buy/sell) fees (0.5% - 0.2%).
The fee is not bad. .4% is below or at least par with what many old industry leaders charge. Most in the industry also have a minimum charge so you will pay more even if you are not storing that much.
Yes there are some cheaper options but sometimes you get what you pay for.