What personal reward does Iago receive as a result of his deceit?

An interesting question. One of the most continually fascinating aspects of Iago is the issue of what he really wants and what he seeks to achieve from his deception. In the opening scene, he says that he is resentful at being, "God bless the mark, his Moorship's ancient," while Cassio, who "never set a squadron in the field," is appointed Othello's lieutenant. We could argue, then, that when Iago succeeds in getting Cassio drunk, such that he loses his "reputation," Iago has achieved a personal reward in that Cassio is demoted from his position—"never more be officer of mine." Iago has succeeded in convincing Othello that he himself is a more faithful and worthy officer than Cassio, who was promoted over him, Iago believed unfairly.
If this is a reward for Iago, it is the reward of seeing harm visited upon somebody else—which seems to be the only reward Iago truly achieves in the play. However, he says himself that he wants to "make the Moor thank me, love me and reward me / For making him egregiously an ass." His reward will come from knowing that he has brought down those he resents, and in this, he is rewarded indeed. At the end of the play, Othello no longer has his wife, Desdemona, having killed her. He no longer has his own life, having killed himself. Iago loses his wife, Emilia, and causes the death of his friend. His behavior seems to have rewarded him nothing in ordinary terms, and yet, if his motivations were simply to destroy those he hates as he "hate[s] the Moor," then, in that sense, he has achieved his reward.