How can a song "debut" at No. 1?!

I’ve read about many a song “debuting” at #1, and it has never occurred to me until now to question exactly WTF this means.
How can a people request a song they’ve never heard before? Isn’t demand for a tune built by prior exposure?

I think it has to do with advanced orders. Retailers speculate that many people will want the new release and order a boatload. Can’t say with all certainty, tho.

But demand for an artist is also built up by prior exposure. So it is pre-existing when their new single comes out.

Companies usually release videos way before the date the single will be available in shops - a song can appear on MTV type channels for months, building up so that everyone runs out and buys it when it is finally released.

Add to this the PR/media campaigns and hype and voila! - debut at no.1.

It happens in the UK all the time, not sure how often elsewhere?

Also, Top Whatever charts are compiled weekly, so a song can be released on Monday, accumulate the most sales/requets/whatever over the course of the week, and so appear at #1 on the first ranking since its release.

Don’t they also play songs on the radio before releasing them as singles sometimes? I could have sworn I was hearing the latest Matchbox 20 song before it was available in stores.

Can’t resist a bit of music trivia here:

What was the first album to debut at number one on Billboard’s Album Chart?

1975’s Captain Fantastic and the Brown Dirt Cowboy by Elton John

Yup, and since radio airplay is factored into chart position this can make an even bigger difference than you might think. For example, Pearl Jam’s cover of “Last Kiss” did fairly well on the charts before it was released as a single on the basis of radio airplay alone. But it’s rare for there to be enough of a delay before a single’s release for something like that to happen. (“Last Kiss” was a special case because it was not originally slated for commercial release at all and was only released as a single because of its popularity.)

Even without the radio airplay factor, I’m sure there are many popular artists who could sell a fair few singles on the strength of their name and fame alone to shoppers who’ve never heard the new song.