After an Upper East Side family lived a Manhattan nightmare — applying to roughly a dozen private schools and getting into none — their admissions consultant said she made one last suggestion: a new school downtown called Claremont Preparatory.

With $40 million invested in start-up costs, 125,000 square feet of space, single-digit student-teacher ratios, comparable tuition rates, and — best of all — several open spots, Claremont should have been a dream. The family did not even apply.

“We’d rather go to public school,” they told the consultant, Victoria Goldman.

Not that they didn’t like the pitch. To the contrary, Claremont is a victim of the Groucho Marx complex: Many Manhattan families just can’t bring themselves to join a school that would have their children as members.

The chief executive officer of MetSchools, Michael Koffler, whose company operates eight for-profit private preschools, created Claremont to be his network’s flagship. From its enormous site in an abandoned bank headquarters near the New York Stock Exchange, it was meant to represent the new Manhattan: family-friendly, diverse, downtown.

With top schools turning away hundreds of families each year, there appeared to be no shortage of interest. Mr. Koffler expected to serve 1,000. Yet in Claremont’s first year, 2005–06, only 54 students attended.

This year, the number was about 125; there were only two students, both girls, in the eighth grade. At the school’s end-of-the-year musical — staged using a lighting and sound system fit for off-Broadway — the eighth-graders towered awkwardly over their tiny peers.

Next year, Claremont expects to grow by at least 100, but several classes have open spots.

“I couldn’t find too many, if any, families who were genuinely interested in Claremont,” Ms. Goldman said.

“My clients have chosen other places so far,” another consultant, Emily Glickman, said.

Mr. Koffler had underestimated his task, Claremont’s new headmaster, Irwin Shlacter, said. “He was told that if he opened the doors, 500 people would come,” Mr. Shlacter said. “But just dropping the school out of the sky doesn’t mean it’s going to manifest itself as a full-fledged school.”

Mr. Shlacter summarized the problem by tracing an invisible arc off his nose. What Mr. Koffler did not anticipate, he said, was “snob appeal.”

When courting the parents who make up Manhattan’s private school market, a school can’t just be good. It has to look good. And as any high school student knows, to look good, it helps to look wanted.

Mr. Shlacter undertook the tricky project of building Claremont’s reputation last summer, after Mr. Koffler fired his first head of school, an experience several parents called “traumatic.”

The next hire was an admissions director from Horace Mann, Dana Haddad. When she learned that an admissions consultant had advised her clients not to look at Claremont, Ms. Haddad immediately telephoned with a sharp rebuke. When she was made aware of a report that Claremont students had low test scores, her response was just as incisive.

“That is absolutely false,” she repeated several times.

Maintaining selectivity — or at least the impression of selectivity — is paramount.

“I could have 750 bodies next year,” Ms. Haddad said. “But we don’t want to just fill the school.” So far, Ms. Haddad says the school accepts about half its applicants.

A main concern is next year’s seventh-graders, who will be the school’s first graduating class as the school adds a high school. If enough don’t get into top colleges, selling Claremont could become even more of a challenge.

At one of their first meetings, Mr. Shlacter and Ms. Haddad shut themselves in a room with one objective: creating a convincing sales pitch, a way of “instilling the feeling in people that this is a success story,” Mr. Shlacter said.

In their telling, Claremont is not the next Dalton, as a New York magazine story suggested last year. It’s an anti-Dalton.

Where the nearly 100-year-old Upper East Side school boasts about its self-named instructional plan, Mr. Shlacter promises to mold a fresh plan for every child — and will do so for less: Claremont’s tuition is $27,800 a year; Dalton’s is about $31,000.

Looking for well-connected trustees? At Claremont, Mr. Shlacter and Ms. Haddad say, no single group or profession has a stranglehold on the parents’ social world — and you don’t have to worry about what designer you’re wearing, either.

The story is working well so far with parents.

David Stanke, who sends his four children to Claremont, praised its “downtown flavor.”

Melani Nardone and her husband, Randy, the chief operating officer of the Fortress Investment Group, have decided to sell their uptown condo to be closer to their daughter’s new school. Ms. Nardone says she’s thrilled with Claremont’s individual attention — so unlike the “my way or the highway” attitude she found at other elite schools.

Testimony like that, Mr. Shlacter says, is the best public relations.