Romanization in the Time of Augustus

Why during the lifetime of Augustus (63 B.C. to A.D. 14) did Roman civilization spread so quickly, influencing art and architecture, religion, law, local speech, and city design throughout the ancient world? In his latest book Ramsay MacMullen argues that this acculturation was due to eager imitation by conquered peoples ably served by Romans' effective techniques of mass production and standardization.