Provided the album meets expectations, it'll mark an important milestone. It should be the first Billboard chart-topper to get the majority of its album sale equivalents from streaming, not downloads or physical copies -- yes, only a fraction of listeners likely had permanent copies. The achievement is somewhat arbitrary (you still can't buy the album at places like iTunes), but it shows that on-demand listening is so popular that you don't need downloads to create a hit.

Also, Kanye might have sworn off CDs a little prematurely. Billboard's tipsters understand that a physical release will "eventually" show up, most likely as a special edition that gives diehard fans extra content that won't be available online. If so, Pablo is less of a radical shift in music and more of a brief experiment with distribution. You might not see future albums released in physical form, but West and crew aren't ready to make that leap just yet.