For example, sell a 90 day or recurring Loot create subscription in the add-on store. Then once a month, subscribers get 1. random consumables 2. item or pet only via loot crate 3. very small chance at a epic item Loot crate is not a lottery. The idea is you items worth the value of what you paid. There is just a chance that you could get something extra special.
The exact same setup as many mmos out there... ESO SWTOR I'm all for more stuff in the addon store but, not like that. SWTOR gave everyone free creds, and I pop those creds into a loot crate that has guaranteed 1 rare item. Turns out SWTOR redefined what the definition for the word 'rare' means, because apparently it means worth zero on the auction house, as there are mass quantities of the 'rare' all are set to the lowest possible unit of currency and there are no buyers.