Just a few suggestions. Since mostly people buy gold for long and mid term, you could add some sort of stacking feature in your website where people can stack their digital gold in order to take some annual profits.
That's a nice idea if they have the capabilities to do that. I think most staking platform also open a lending platform, but for Gold I don't think it's a good thing to launch for now. It would probably easier to do it if Gold cooperate with existing staking platform instead such as Honest Mining. But that being said it I never knew a staking platform that accepts coins without in-built staking function.