My cofounder and I used to manage a £100k/year ad budget and we did TV, news papers, radio and Facebook. The level of engagement and ROI on Facebook was insane compared to the others specifically because we could tweak and cohort up the audience so specifically - we even commented how terrifyingly powerful it was and that it was a good job we were only selling a home efficiency central heating product because in “the wrong hands” it could clearly be devastating - you just don’t get that level of granularity with more mass media outlets, even when you break it down by readership/demographic