Ding Jinlin has earned more than 200 five-star ratings from her customers since June after registering as a part-time ayi, or housekeeper, through an online tool that helps connect people with service providers.

The tool for booking housekeepers, located at 58.com, works something like Uber, the taxi-hailing app. The customer pays a fee up front when scheduling a housekeeper, and the worker keeps all the money earned on a job.

Ding's careful attitude and her cheerful personality have won many regular customers. She's fully booked for at least eight hours a day, including weekends, for the next two weeks.

"Today, young people perhaps never clean their own homes," she said, adding with a laugh that "young women are all very pretty when going out, but usually their rooms are much messier than young men's".

An old problem for operators of online booking services for housekeepers was that if customers were unsatisfied, they would not use the service again; or, if they were satisfied, they would contact the ayi directly to bypass the brokerage fee.

"I get 100 percent of my earnings," Ding said. "Plus, I receive bonuses based on customer feedback, so it's not a good deal to accept offline orders".

She said she earned more than 8,000 yuan ($1,258) in September. The average salary of business employees in Beijing was 6,463 yuan in 2014.

The website this month adjusted service fees for all ayi with a "gold rating", such as Ding, from 35 yuan per hour to 25 yuan to attract more orders. That means she can only earn 5,710 yuan if she worked the same number of hours as last month.

The company has not increased its bonus to offset her declining income, leaving her a bit unhappy and unsure about the future, she said.

Rapidly growing online-to-offline services enjoyed skyrocketing growth in the first few months of this year thanks to abundant capital in the industry, which allows online service providers to ignore commissions from its users and provide subsidies.

However, analysts have warned that startups now need to tighten their purses because fundraising is likely to become more difficult as investors have become more cautious after the big fluctuations of the stock market earlier this year and a slower-growing economy. China's economy grew 6.9 percent in the third quarter year-on-year, the weakest rate since 2009.

Shen Lingkun, an analyst with market research company Zero2IPO Group, said venture capitalists have tightened their investments in the third quarter. The total number of venture capital investment transactions during the quarter in China was 716, a decline of 20.4 percent compared to the previous quarter.

The Internet industry attracted 257 transactions, followed by IT and the telecommunication industry. The three accounted for about 66 percent of the total capital investment in the third quarter.

China's largest online ride-booking company, Didi Kuaidi, raised $3 billion of fresh investment through its latest fundraising round, which is by far the world's largest transaction for a non-listed company. Didi recently cut its subsidies to registered drivers and passengers despite its abundant cash flow.

New emerging business models also face regulatory uncertainties that could greatly increase costs. One example is recent draft rules released by the Ministry of Transport that require car-hailing service providers to sign labor contracts with the drivers.

Wang Yumei, a senior analyst with Huatai Securities Co, said at a recent forum that most O2O service providers are the cash burning type that require a round fundraising every three months.

But relying on subsidies is unsustainable, particularly at a time when financing has become more difficult. Cash-burning startups should spend more efforts on improving customer experience and optimize their business models, she said.

Contact the author at lanlan@chinadaily.com.cn