Speed: Bullet to Correspondence Rating:
The d5 pawn push, not only occupies the center, it directedly attacks the e4 pawn.
The Scandinavian is a great opening for the active Black player. White's only appealing move is exd5. After which the Black queen may find's itself in the middle of the board, on d5, after capturing the White pawn. Having the queen out early is contrary to the opening principles often thought to chess students, however the Scandinavian is one notable exception to this rule.
Nevertheless, in the next few moves, it's common to see White try to gain extra tempi's by attacking the Black queen. Often starting with Nc3.
In the Scandinavian Defense, Black will often castle queenside. Thus immediately having the Black rook on the semi-open d-file. This also allows black to initiate attack on white's kingside.