Me: So when people bring a bottle of wine to a dinner party, it's a way of showing gratitude but still bringing something that costs less in money and effort than their share of the dinner, so that the people throwing the party can still be seen as offering a gift to the guests.
My mother: When Russians throw a dinner party at a restaurant, everyone is expected to bring a check for the cost of the meal, plus some extra for the hosts. It's like a fundraiser.
Me: So basically, throwing parties could be a for-profit enterprise? You could make a living by just inviting people out to restaurants?
My mother: Yes, I think it was a Soviet idea.