Not because you've pressured or outsmarted your opponents. Hamas have won. It got what it wanted. It chooses the intensity and timing of the conflict with Israel. Hamas didn't want to kill Shalit, that was evident from the start. They would have released him in any case. But releasing Shalit after Fatah has failed at the UN showed the Palestinians that Jews can be handled only by the use of force, not by negotiations.
Saudi FM: We hope Iran uses sanction relief for development, not nefarious activities (Reuters)
from the article: Netanyahu: Shalit's release means I have accomplished my mission