A family based in London recently gained attention for offering nearly $240,000 a year (£180,000) for a private tutor willing to prepare their toddler for Eton, one of the world’s most elite boarding schools, once attended by Prince William.

“Having started at age 5 with this child’s older brother, they felt that even this was too late to achieve their goal, hence their search for a tutor now,” the listing reads.

Behind the listing online is a company called “Tutors International”. They describe themselves as a “special tutoring company” that caters to high-net-worth households who want a full-time, bespoke private tutor. The company vows to give its clients the “highest level of service of any tutoring company.” 

The instructor’s compensation is far from unusual for them. Most of their postings are in the six-figure range.

To earn the six-figure salary, the “extraordinary” tutor must have a posh Received Pronunciation accent, reasonable knowledge of music theory, experience in royal or embassy households, and the ability to introduce a one-year-old to cricket, polo, and rowing. The overall goal is to get the child ready for an elite institution. 

“The family are not British, and they enormously value Britishness,” Adam Caller, CEO of Tutors International, told Fortune in an interview.

As white-collar jobs become increasingly oversaturated, the posting highlights how lucrative side hustles are taking place not only in corporate boardrooms but also in the living rooms of the ultra-wealthy.

Tutors International currently has more than 50 tutors worldwide. Caller has been running the company for 26 years. He says that even before the post went viral, his business saw up to 300 percent growth in clients. 

The reason: wealthy families want to set their children up for success in the increasingly complex world of elite private schools and Ivy League admissions. 

“How early is too early? And the fundamental answer to the question is, it’s never too early,” he added. 

Six-figure posting are common for this tutoring company 

Caller said that while the young age of the child is a notable part of the viral job posting, the high salary and elite demands are not.

“Everything else about it is so remarkably normal for us,” Caller said. “It might not be normal for other people reading it, but for us as a company, it’s such a common kind of request,” he said. 

Currently, Caller says the posting has about 140 applicants, which is lower than the 320 he saw in a June posting. Since the posting went up in the middle of the school year, recruitment has become more difficult. 

“This [pay] is on the low end of the spectrum,” he said. 

“In June this year, I posted a job not far away—physically, in another part of North London—paying £288,000 a year. Nobody noticed it. I’ve got jobs all over the world, typically in the two hundreds of thousands of pounds a year. £260,000 is not uncommon,” he said.