In households prior to the modern period which has demanded a large turnover if women to the work force, typically the mother or lady of the house was responsible for many financial aspects of the household. While men engaged with worldly affaurs, women were bargaining at the markets, accepting and paying for deliveries to the house, giving to charities, and often paying wages to staff (if there were any). She ran the house presumably like a well oiled engine.
Therefore when people praise and give coins to Mercury for his slick buisness acumin, it is a very different monetary function than with Iuno Moneta. Mervury will aid the growrh of business and aid business savy, but Iuno oversees every penny of the household budget and manages the overall wealth of the house. Mervury brings it in but Iuno invests it, divides it and pays expenses and saves. My mother was born in the Orohic month of this goddess and never have I seen money saviness such as she possesses…truly a gift from this goddess.
By all give coins to Mercury but lets not forget a small money box or coin pouch for Iuno.