Pasalubong is common to all Filipinos. I do it to friends and relatives who travel too. It is the Filipino culture's form of "parayg" or endearment when they ask you for pasalubong (gifts). It's our way of appreciating them for being able to go and see the world. It's a tap on the shoulder saying, "Good job! Have fun!" It is received as a flattery but we have to watch for it so as not to overdo it. Make sure you are not putting pressure on the traveler.