Most pop tunes follow a basic format. They're usually indicated using:

A) AAA
B) AABA
C) V/C
E) OTHER..........

..or in other words, Verse/Verse/Verse, or Verse/Verse/Chorus/Verse etc...

There's exceptions but most hit songs follow at least one of the accepted formats cause that's what people have come to expect and it's what radio programmers want.

There's a whole bunch of stuff I learned years ago in songwriters workshops...
like coming up with a universal emotion that millions of people can identify with... summing up the songs title so you can remember it after hearing it once... sticking to a certain time frame, like the present or the past or future... sticking with one viewpoint like "I, you, they, she" etc... setting a certain 'tone' like romantic, ironic, playful, reflective etc...
Crossing the music over more than one chart so you maximize your sales...

You have to break the rules sometimes but if you look at any hit song from the past, almost all of em follow the same basic formats.