I've noticed that most of the other posts are about information, or artificial reality, or something like that, but I've decided to post on something that's a little closer to the range of my interests.
Throughout the novel, YT is the object of desire by nearly every single man around her. As one example, the one-eyed man calls her "a hell of a chick. You're a knockout" (171). Everyone is constantly looking at her, so much so that she feels its loss on the Raft, where everyone except Raven is entirely sexless. The novel seems to portray this overt sexuality as nothing more than a fact of life. If anything, it's a joke, even though the girl in question is not more than 15 years old. She is constantly mentioning sex with her "boyfriend" Roadkill (73,162), and expects Hiro to pursue a relationship with her when she first proposes a partnership - "this is going to end with him trying to get her into bed" (87).
Essentially, sex in this novel is portrayed in a relatively positive light. Though blatant sexual desire is mostly associated with unpleasant people (the jail operator in the Clink, the security guards at the Mafia compound, the people in the truck stop, etc.) their desire is essentially harmless, and in fact provides a convenient tool by which they can be exploited.
There is one unpleasant person that I have yet to mention, and the only person that inspires serious sexual desire in another character - Raven, who makes YT "uncomfortably horny" (343). Despite the fact that he basically kidnaps her from her job on the food line, she repeatedly speaks of going on a "date" with him (323, for example), and even in one instance describes him as her "boyfriend" (343). Being attracted to him, and knowing that he is attracted to her, has produced some desire for her to continue their relationship, even though she knows of Raven's reputation, and has seen some of his work.
It seems to me that the mechanisms of commitment in Snow Crash are relatively simple. When two characters have a mutual sexual desire, this inspires the further desire to be committed to that person. This desire overwhelms any conflicting information that either party might receive.
Contrary to what you might expect, I think that the desire for commitment is actually quite strong between Raven and YT, as demonstrated by their final interaction. Raven is in a helicopter, flying over as the Kouriers swarm L. Bob Rife, but he's "not watching any of these things. He's looking out the window at Y.T.... He grins at her and gives her the thumbs up. Y.T. bites her lower lip and flips him the bird" (424). I really think that at this point, Raven admires her. She does not seriously threaten him, and yet she bested him in a sexual contest. In their final interaction, I see a reluctance for Raven to leave Y.T., and a similar reluctance for her to let him go. Why else would Raven focus his attention solely on her? Why else would Y.T. bite her lip as she flips him off? In the vein of the novel, they have been sexually involved, with mutual desire, and that inspires them to continue their association. I should note that YT is far more commited to Raven (desires him, wants to be with him) than she ever really is with her "boyfriend" Roadkill. She has not had a satisfying sexual relationship with Roadkill, and so she's not nearly so invested in their relationship.
Overall, I think that Snow Crash provides the "teenage boy" perspective on sexual attraction as it relates to commitment. It is not nearly so nuanced as many of the other novels that we've read, but I thought it was interesting that there was so clearly a relationship between sexual satisfaction and commitment. It anchors the spectrum at one end, I think, while The Handmaid's Tale anchors the spectrum at the other end, where sexuality acts constantly to break up commitments, or to prevent nascent commitments from being realized in a healthy manner.