Though queenside castling is less common, it is important enough to study. If your opponent has castled queenside, sometimes you have an opportunity to expose their King by sacrificing your Bishop for 2 pawns, as showed below. (I have removed other pieces from the board to avoid distraction.)
[FEN "2kr4/ppp5/8/8/8/4B3/8/4K3 w - - 0 1"] 1.Bxa7 b6 2.Bxb6 cxb6
What factors should one consider before deciding to offer this sacrifice? To put it another way, in what positions is this sacrifice favourable and in what positions would it be unfavourable?
Edit As per comment from xaisoft, I am posting a board with other pieces.
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"] 1.e4 e5 2.d4 d6 3.Bc4 Nf6 4.Nf3 Nc6 5.dxe5 dxe5 6.Nxe5 Nxe5 7.Qe2 Bd7 8.Nc3 Qe7 9.Be3 O-O-O 10.Bxa7 b6 11.Bxb6 cxb6