Giving gifts is a significant component of communication between us humans. It defines and strengthens (or weakens) our relationships with friends, family, and lovers. We tend to give gifts to individuals we want to connect with; not just the romantic ones, any kind of relationship.
You voluntarily offer something when you offer gifts without wanting anything in exchange. It's more than enough reason to make someone feel unique to make you give more. To be precise, gifts are valid tokens of affection without any expectation of compensation. That is why the whole process of choosing presents is something that should not be a chore; it must come straight from the heart.