Gifts are like Hooks

What does it mean?

My English department, for some odd reason, bases it's entire English curriculum around proverbs and sayings. What's interesting is that most of the time none of us really understand the meaning of the proverbs, but we have to teach them. What is the meaning of this one:

"Gifts are like hooks."

I couldn't find much information on it when I googled the proverb. I suggested that it might mean that when you give someone a gift, you "hook" them in, meaning you catch their interest in you.
My supervisor didn't agree with me thought. What could it be?

In some cultures giving a gift creates an obligation on the receiver to repay the "kindness". A person who accepts a gift is like a fish caught on a line - now the giver/fisher has power over you.

There's a Norse poem about a man who receives a beautiful sword as a gift. He curses the giver. "Aw man, now I've got to come up with some even more beautiful gift for you. I don't even like you. Why did you put me in this position?"

I think it means: when you give a gift, someone is indebted to you.  You've hooked them like a fish.