Yours, Etc.: Origins and Uses of 8 Sign-Offs
c.1600, "reward given for a specific act," from Latin praemium "reward, profit derived from booty," from prae- "before" (see pre-) + emere "to buy," originally "to take" (see exempt (adj.)). Insurance sense is 1660s, from Italian premio. Adjectival sense of "superior in quality" is first attested 1925, originally in reference to butter.