Consider B. K., a fit finance executive in his early 40s, who, last October, began “dating” a 20-year-old engineering major at a college 90 minutes from his house. Like nearly half the sugar daddies on Seeking Arrangement, B. K. is married. (Neither B. K. nor any other user of the site would allow full names to be published — certain the revelation would infuriate wives or boyfriends, shock colleagues and repel friends or family — and agreed to use only their first names, nicknames or initials.) B. K. and his wife opted against separation, for the sake of the kids, and for now, they have a policy — at least in his mind — of don’t ask, don’t tell. Between pangs of guilt about cheating, B. K. views his secret dallying as a safety valve, letting him feel desired so he can return home and appreciate the many things he loves about his wife, even if they don’t include giving him the attention he wants.

And so, nearly each week, B. K. gets together with Lola, the young woman he met on the site, for a meal or a gym workout and a few hours at a hotel outside the Western city where he lives. Their visits are generally no longer than four or five hours because Lola, a senior, has a full course load and also works 40 hours a week at two low-wage jobs. With no money from her parents, she was frank in her Seeking Arrangement profile, saying she needed “immediate financial assistance.” In B. K., she gets that in the form of $100 or $150 stuffed in her bag each time they meet. He feels good about helping her with her tuition, encouraging her studies and romancing her, albeit in hotel rooms. Most of all, he’s grateful that she doesn’t want a commitment. At least he was at first.

“It’s very clear with this site that she’s getting something out of this, hopefully emotional support and mentoring advice and fun in bed, but also something financial, so don’t come back to me and say that you were used or that I left you high and dry,” he said. “I like that aspect of it, but on the other hand, it would be nice not to have the money involved, because you always wonder: would she still want to be with me even without the money? Does the money make me more attractive than I really am?”

ABOUT 30 PERCENT OF ARRANGEMENTS on the site involve the daddy paying an “allowance,” usually a thousand or two a month, though the site claims some reach $10,000. The rest provide the baby with incidental cash, shopping sprees, gifts, travel or the fleeting illusion that theirs is a high-end, easy life. “I get flown to whatever city I want,” wrote a North Carolina college student, who goes by the name gurlnextdoor on the site’s blog, a mix between an online support group and a kaffeeklatsch. “He pays for it, takes me shopping, we talk, laugh, go out to eat and do whatever we want to do for our days together. . . . I don’t bring up mundane problems about my home life, and he does the same. . . . If I wanted someone to talk to about my life problems, I’d get a boyfriend or a therapist.”

Like B. K.’s companion, Lola, many women on the site are in their 20s, though plenty of others are in their 30s, 40s and 50s. Some are looking for attention, some have financial problems and some are seeking refuge from romantic pain. On the blog and in conversations with me, still others said benefactors provide a way to get the extras they want — the Fendi bags, the to-die-for shoe collection or the breast enhancement. A surprising number of babies say on the blog that they don’t need the money at all, either because they have decent-paying jobs or bottomless credit cards from their parents. What appeals to them about the arrangements are the expensive gifts — “I just LOVE being spoiled,” gushed one 19-year-old woman on the blog — because those gifts make them feel valued, as if the money spent measures just how desirable they are.