Some roles in theatre just stand out from the rest, and Ricky Roma is one of them. He's not the protagonist and he's not the antagonist, but there's a good chance the actor playing Roma is going to get top billing on the marquee and the posters when Glengarry Glen Ross comes to town.
This guy is slick—like, smoothest guy in the room slick—and he can talk about anything and somehow turn it into a sales pitch. His first duet scene with Lingk is really just a glorified monologue. Lingk might throw in a word here and there, but really it's just Roma talking. And what does slick Rick talk about? Life, sex, food, everything. Heck, he doesn't even get around to introducing himself until the scene is almost over.
Mamet introduces Roma long before he ever shows up, when Levene mentions him in the opening lines of the play:
LEVENE: John… John… John. Okay. John. John. Look: (Pause.) The Glengarry Highland's leads, you're sending Roma out. Fine. He's a good man. We know what he is. He's fine. (1.1.1-5)
So right off the bat, we know Roma is the man—he's getting the good leads. It's not until a couple of scenes later that we understand why. Roma sits alone in the Chinese restaurant talking to a stranger sitting in the booth next to him. This is how he starts:
ROMA: … all train compartments smell vaguely of shit. It gets so you don't mind it. (1.3.1-2)
Mamet drops us in right in the middle of Roma talking, and we have no idea where he is going with this. Along the way, Roma talks about women he has slept with, great meals he's had, and how life is "looking forward or it's looking back" (1.3.39-40).
Still, we don't know where Roma is going; we're simply listening and following the subtle winding turns in his language. Eventually he gets to his purpose—the sale:
ROMA: Stocks, bonds, objects of art, real estate. Now: what are they? (Pause.) An opportunity. To what? To make money? Perhaps. To lose money? Perhaps. To "indulge" and to "learn" about ourselves? Perhaps. So fucking what? What isn't? They're an opportunity. (1.3.70-75)
This serves as a nice glimpse into that sweet Roma style, and we see him just hinting at what's about to come. He subtly drops real estate into the mix, putting virtually no pressure on it at all. He's just a man talking about opportunity—something that everyone is on the lookout for. With his seemingly winding style of talking, Roma is actually luring Lingk in. He sets himself up as a guy who shoots straight—he's not pushing a hard sale, he's talking about life, and how life might be able to get a little bit better.
Soon after this, Roma introduces himself to Lingk, the man he's been talking to, and then he drops the Glengarry Highland's (remember the good leads) pitch on him. We learn in Act 2 that the pitch was successful and that Roma closed the sale. Roma's approach to Lingk provides us with the clearest vision of how these guys operate:
Observing Roma in action permits us to experience vicariously the salesman's thrill of the chase. He shows us how talk can transfer needs from the salesman to the potential customer and power from the potential customer to the salesman. Realizing that Lingk does not believe he enjoys or is in control of his life, Roma engages in a philosophical monologue in which he talks about the meaning of life, risk-taking, and seizing the moment. Roma plays to Lingk's insecurities. (Source)
We never get to see Roma with any other potential clients, but one can imagine him tailoring his speech for every different person he pitches to. Roma hunts. He's like one of the big cats chasing down prey, and like the big cats, he's smart enough to go after his target's weak spots. Roma has a sense as to what kind of guy Lingk is, and he finds the specific words that Lingk needs to hear.
Of all the characters in this play, Roma best defines the world of the salesman: He is always on. He's quick on his feet and willing to do whatever it takes to make and keep a sale—he concocts the make-Levene-pretend-to-be-a-client-in-order-to-trick-Lingk scheme in a matter of seconds.
There are reasons Roma is king of the board—he's arrogant, ruthless, and good at his job, all things that make him envied and disliked by Moss, who sits right behind him in spot #2:
MOSS: You're hot so you think you're the ruler of this place… ?!
Roma definitely does come off as the ruler. Even Williamson lets him get away with stuff the others can't. When the cop is bugging Roma to go talk to him, Williamson deflects it so Roma can do business with Lingk.
Business is the important word when it comes to Roma. Dude is always on the job. Mamet gives us a moment when we might fall under the impression that Roma is somewhat human with the way he interacts with Levene, giving Levene credit for teaching him what he knows and saying he thinks they should work together:
ROMA: I said, "The Machine," there's a man I would work with. There's a man… " You know? (2.1.1185-1187)
Of course, in the end Mamet shatters any illusions about Roma we might have. Roma has other motives here. He's building Levene up, making him feel like a leader again, but it's just because he sees profit for himself in a "partnership" with Levene. His last words about Levene are to Williamson:
ROMA: My stuff is mine, his stuff is ours. I'm taking half of his commissions. (2.1.1238-1240)
Brutal, right? Roma doesn't care about anything other than being on top of the board, getting the Cadillac, and closing.