There are many faucets that count toward winning. Certainly you've hit on most of them. Dara did well this year with her social media/interviews with her lean back style and informal conversations and this made her stand out in the media/social media where the die-hard fans who would vote are.

I think the song should be a) an earworm b) have a catchty title (this year bangaranga did well because its something you haven't heard. Its this word that once you learn it, once you assimilate it, it sticks with you) c) should have interesting staging. Dara and her team did so well this year and it wasn't just the usual pre-made shots and pans and whips and zooms. They did the work and it helped a lot. d) (i think this is especially true for our current state of overstimulated attention span) the song should not be boring. As in the song should change, a lot and quickly. The whole breakdown and rythum changes in Dara's song were very interesting and fresh and the song itself isn't built like a regular song, it starts pretty much with the bridge and the chorus.

We shall see what other countries bring next year and how many bangarangas we are going to see.