A gift certificate for dinner for my family at The Salt Lick (one of our favorite local restaurants) arrived from a friend who lives on the east coast to whom I referred a piece of business. He could have said "thanks" in many ways, but he made it local and personal. This took extra effort to orchestrate, but is showed class and real gratitude.
A text saying "THX" is better than nothing.... but a little effort makes the other person feel good, and gets you remembered.
Have A Great Day