iPod Someone explain the top songs?

[longball11]

When a person goes to look at an artist's albums, etc. there is a top songs area. Is this list based on popularity? best song? most purchased? what is based on?
The thing that confuses me is when a new album comes out, a song off that album will go to the top of their top songs list. But down the road, it goes off the list and their old songs are back on top. It just disgruntles me because I usually purchase a song off the artist's new albums if they are in the top 5 and remain there. Yeah, call me obsessive and picky but I do it to control my budget and not waste money on an entire album where I might not like some songs and skip them all the time.
How is the top songs worked?

 

[yellow]

Thought it might be a couple factors, the easiest is probably the one purchased most. That's why newer albums might have even popularity across the board, because most people purchased the album rather than individual songs.


Conjecture:
Additional factors might be rankings in people's iTunes that are allowed to have their Genius junk downloaded back to Apple.
Deals with album execs to push "singles" from the album.

 

[longball11]

Thought it might be a couple factors, the easiest is probably the one purchased most. That's why newer albums might have even popularity across the board, because most people purchased the album rather than individual songs.


Conjecture:
Additional factors might be rankings in people's iTunes that are allowed to have their Genius junk downloaded back to Apple.
Deals with album execs to push "singles" from the album.

Usually I buy one song from each artist. But I'm hesitant with the new Dream Theater album. I love the "A nightmare to remember" and "Count of tuscany" songs but their album only because they are long songs. It really ticks me off when albums and songs put that tag on songs longer than 10 minutes. Wither is alright but I like Rite of Passage better and it isn't in the top 5 list though it was a single...
I can't wait for the new alice in chains album, their new single rocked!

 

[BayouBengal]

Sometimes, but not always, the long songs marked album only in iTunes are available individually thru Amazon MP3 Store.