Why multiple fee's for delivery to the same address

My experience with Netflorist earlier today was great. Great service and very quick delivery. One issue i find a bit "unreasonable" though, is when you order multiple items for a single address / single person, you are charged a delivery fee for each item you order. So although i ordered 2 gifts for my daughter for her birthday (for delivery to the very same address), i was charged R89 for each item. This is believe is not reasonable given that the delivery was going to the single address in the first place. Other than that - thank you.