How much was total digital ad spending in 2013?
A) $40.1 million
B) $42.8 million
C) $18.4 billion
D) $40.1 billion
E) $42.8 billion
E
Business
A) $40.1 million
B) $42.8 million
C) $18.4 billion
D) $40.1 billion
E) $42.8 billion
E