In the era of Donald Trump, it's kind of crazy to think that the US President can be so easily led and cajoled by the TV he consumes that a HBO political comedy show could conceivably influence him by buying ads during his favourite show.
In order to try and convince the US President not to back out of the Iran-US nuclear deal, John Oliver's purchased advertising on Sean Hannity's Fox show - the show which Trump watches on a daily basis - in the hopes that it'll directly reach him or the people around. If you think getting that pointed with the Trump administration is a bold move, it's not the first time Oliver's tried it.
Just recently, he wrote a competing book to Mike Pence's one about his rabbit - which eventually became so successful that it completely passed the original one in terms of sales - that took a firm aim at Pence's anti-LGBT stances and prejudices.
Skip to around the twenty-minute mark to see the advert or just watch the whole thing through as it's very entertaining - and educational.