Cash is nice, but nothing corrupts like a free lunch:
Yes, lunch conquers all, more than love. When, as happens occasionally, some politician’s corruption stands revealed in the press, what shocks me about it is often the trifling amount by which he has benefited and by which he had allowed himself to be corrupted. Just as it is the small insults, humiliations and acts of disdain that people have suffered rather than frightful injustices that move them to political anger and even violence, so it is small obligations that are more corrupting than large. Large sums of money transferred to a secret account are impersonal; lunch is a social event.
To paraphrase Nietzsche:
Be careful what you eat, as it may eat you.