Why does Socrates suggest that he receive free meals at the Prytaneum?

In ancient Athens, when the jury voted for a penalty, the accused could offer an alternative penalty; the jury could then decide between the two. So when the jury voted for the death penalty, Socrates could have proposed the alternative penalty of exile (and the Athenians would probably have been satisfied with that), but Socrates held that he had done nothing wrong and had, indeed, done a tremendous service to Athens. Therefore, in place of a counter penalty, he states that if justice is to be done he should be granted free meals at the Prytaneum--an honor given to benefactors of the city and to Olympic victors.