Ad spending expanded 3% during the third quarter of 2014 among the advertising agencies pooling their data in Standard Media Index, reports B&C magazine.”Digital” ad spending expanded 20%, including big jumps on YouTube (+59%), Facebook (+47%) and Twitter (+44%). TV ad volume fell 1% in the quarter, including an 8% decline in spot TV billings, and a 4% decline among broadcast networks. Cable networks appear to have expanded their share of national TV, rising 2% in the quarter.