It ultimately depends on your beliefs as there is no definite answer. However what you described seems like a well accurate assumption. Some people see demons as simply spirits however, and others leave offerings to please and respect their gods.
I have found that it can also depend on the entity itself. Like us, they have their own personalities, likes, dislikes, etc. With some they prefer physical offerings of whiskey, stones, herbs, etc. Others simply are comfortable with our continued devotion and thanks for their assistance and presence in our lives.
I personally write poetry and verse for the spirits and entities I work with. I combine this with acoustic guitar music, and I have found that invoking them in such a way works better than other methods for me.