3 syllables we all long to hear

3 words that everyone longs to hear. We say it to our friends, our family, our pets, or significant others, but has the meaning changed overtime? Advertisers use it to sell perfume, jewelry, anything that they can think of. People use it for other reasons than to tell someone how they feel. They use it for a reason why they should stay together, even if they aren't right for one another "but I love you babe". They say it order to get stuff they want "If you love me you'll do this for me." So are we suppose to use the same words that we say to our dogs, or advertisers use in order to say how we feel? How can these 3 words make us feel so warm and fuzzy on the inside?