With virtually all communication shifting to email, text and maybe -- just maybe -- phone calls, the thank-you note has become a rarity. (Even rarer: Actual letters, but that's another rant for another time.)
You hold in your hands a letter. Not an email, not a Facebook message, not a DM. An actual, physical missive. It is an epistle, of the ilk our fathers and their fathers once wrote. In short, this is a real "brick and mortar" affair you are looking at.