The DISADVANTAGE is that your pawn is on e5, without the support of one on either d4 or f4, meaning that the pawn has to be protected by pieces, one of which happens to be your queen. If you are not careful, your queen could be "developed" prematurely. And it does block your light squared bishop for the time being.
That said, there are some potential advantages as well:
1) It prevents a Black knight from moving directly to f6.
2) It indirectly discourages Black from moving a pawn to d6 or f6, because if you capture, he can't recapture with the e pawn, which would be pinned by your queen. Also, if he moves one of those pawns, you could get into a gambit by playing the pawn to e6, etc.
3) A likely scenario is that Black plays e6, then moves his knight to e7 (instead of f6), meaning that you've cramped his game in a major way. Black might move his knight further from e7 to g6 and eventually capture the pawn. But he's disrupted his pieces in a major way and lost time, which you might then be able to use finish your development ahead of him and start an attack, perhaps against his king. Under some lines, the early move by the queen turns out to be an advantage.
This is something of a gambit in the Sicilian. All in all, it's a complicated, tricky opening move. But it may be a good one to use for a surprise.
Another gambit that you might use in the Sicilian is the wing gambit, 3. b4, favored a century ago by the American master Frank Marshall. If Black captures with either the pawn or the knight, he's lost time.