I think by this time last year we had: Suit and Tie, Mirrors, Started from the Bottom, Heart Attack, and Love Me score multiple weeks in the sales T10.
It's not that impossible.
That's pretty normal I think. Most of the biggest hits of any year usually come from the previous year.
For example out of the 10 biggest hits of 2013, Can't Hold Us was released in 2011, Thrift Shop, Radioactive, Harlem Shake, Just Give Me a Reason, When I Was Your Man and Cruise are from 2012. Only Blurred Lines, Mirrors and Roar were real 2013 songs.
It's really difficult to get a song to become a big hit in just a few months. Only the established hit-makers like Katy Perry, etc. can get songs to be big straight away.
That's not entirely true. I don't consider Robin Thicke, Lorde, Daft Punk, or Avicii 'established hitmakers.'
Just because something has a synth and a beat doesn't mean it's "EDM". "EDM" isn't a real term anyway, it's a lazy, Americanized way of referring to dance music which ignores all the distinct genres like House, Acid House, Techno, Electronica, etc.
how long has it been in top 20?
their album is discounted, buy it if you like good music 
What the ****