Todd Spangler / Variety: Roku reports Q3 revenue up 24% YoY to $1.5B, Platform revenue up 23% to $1.3B, ad revenue up 23% to $727.4M, and subscription revenue up 23% to $580.9M — For the third quarter, Roku handily topped Wall Street earnings expectations, with top-line growth of 24% to $1.50…