that may be a little bit of an over exaggeration and it takes in some other factors, like how many charts people have had in the past and recently, but that's the gist of it.
its kinda based on total activity and following of the people who liked the song. basically how active and popular all the people who liked your songs are.
that's why viista's boom got #1 in trap and my song SNTH got #2. even though i got 60 likes in a week and viista got 25, his charted above mine because people like Jetdarc, 1trillionMPH, sebosito, etc. liked his song whereas mine was liked by tons of people who just joined and have 0 followers.