What was the single-digit year-over-year growth for home appliances as a category in the first quarter of 2022 
o the inflation has picked out. So, we will closely monitor this with our brand customers.
One more thing is worth noting is that our customer-facing value-added services, for example, cloud storage, recorded an overall 200% year-over-year revenue growth in the first quarter. This performance indicates that end market has robust demand and the feedback for these high-value IoT services. So for home appliances as a category with relatively high overall value also have a single-digit year-over-year growth in the first quarter. And also, despite our brand customers are facing huge challenges -- they are conservative in terms of placing orders to OEMs, but the majority of them are keeping very optimistic for the long-term trend of IoT.
So, for example, last two weeks, myself and our president, we -- through Zoom, we have discussed with six of our top brand companies' CEOs. They are all still focusing on R&D to expand new IoT SKUs and ask us to recommend more exciting, new different types of IoT devices for them. And based on statistic number in the first half of this year, for all the branded customers, we acquired before end of 2020, about 48% of them have expanded into new IoT devices, SKUs this year. So that gives a lot of confidence that even in a very challenging period, the trend of IoT is not changing.
So that's our view for the short-term future of the IoT market.
Unknown speaker
Thank you, Jessie.
Jessie Liu -- Chief Financial Officer
 Thank you, Riya. Operator, let's go to the next one.
Operator
Thank you. Our next question comes from CICC. Please go ahead.
Unknown speaker
[Foreign language] as your newly launched the private cloud if services, how should we expect in the mid to long run? The revenue proportion as revenue. And do we see more from existing public cloud customers switching to private cloud solution? Or we could expand to a new customer profile. What is the marginal change to the gross margin and expenses? Thanks.
Jessie Liu -- Chief Financial Officer
Thank you. Most of our private cloud services customers or new customers, almost all of them. So we are promoting the Tuya Cube product not to our existing customer base, but to new industry or new customers. And our acquisition efforts are progressing smoothly in China and outside of China right now.
We have signed the legal contract with dozens of customers. All of them are very well-known large-scale industry leaders in China and also outside of China. These customers included the largest telecom operators in -- like Indonesia and in China. The -- one of the largest utility group in China and also a couple more similar utility groups are in discussions with us for signing contracts and the leading top three automobile group in China and in Southeast Asia.
So, we are currently also have a very healthy pipeline for large-scale companies, including leading energy companies in the stage of negotiating contracts and also a very large European retail groups. They have thousand large-scale retail stores in -- across many countries in Europe. So, this kind of has all demonstrated our private cloud technologies can be implemented in many different industries, which we feel very excited that the Tuya Cube product can enable Tuya grow outside of consumer electronics industry. In the past seven years, we have been very focused on consumer electronic industries.
And we all have seen consumer electronics industry can be impacted significantly by high inflation, by the economy cycle, the consumer down cycle in China. However, many other different industries, for example, utility industries, the auto industries, and the telecom industries, they are less vulnerable and more sustainable to this kind of economy cycle. So, we believe our focus on the Tuya Cube solution which will not only provide a lot new growth field for us, but make our business in the long term, much more sustainable in a down cycle of economy. So, we will take the Tuya Cube as one of our most important strategies for the next few years.
And we believe this will bring us the new growth support for th
o the inflation has picked out. So, we will closely monitor this with our brand customers.
One more thing is worth noting is that our customer-facing value-added services, for example, cloud storage, recorded an overall 200% year-over-year revenue growth in the first quarter. This performance indicates that end market has robust demand and the feedback for these high-value IoT services. So for home appliances as a category with relatively high overall value also have a single-digit year-over-year growth in the first quarter. And also, despite our brand customers are facing huge challenges -- they are conservative in terms of placing orders to OEMs, but the majority of them are keeping very optimistic for the long-term trend of IoT.
So, for example, last two weeks, myself and our president, we -- through Zoom, we have discussed with six of our top brand companies' CEOs. They are all still focusing on R&D to expand new IoT SKUs and ask us to recommend more exciting, new different types of IoT devices for them. And based on statistic number in the first half of this year, for all the branded customers, we acquired before end of 2020, about 48% of them have expanded into new IoT devices, SKUs this year. So that gives a lot of confidence that even in a very challenging period, the trend of IoT is not changing.
So that's our view for the short-term future of the IoT market.
Unknown speaker
Thank you, Jessie.
Jessie Liu -- Chief Financial Officer
 Thank you, Riya. Operator, let's go to the next one.
Operator
Thank you. Our next question comes from CICC. Please go ahead.
Unknown speaker
[Foreign language] as your newly launched the private cloud if services, how should we expect in the mid to long run? The revenue proportion as revenue. And do we see more from existing public cloud customers switching to private cloud solution? Or we could expand to a new customer profile. What is the marginal change to the gross margin and expenses? Thanks.
Jessie Liu -- Chief Financial Officer
Thank you. Most of our private cloud services customers or new customers, almost all of them. So we are promoting the Tuya Cube product not to our existing customer base, but to new industry or new customers. And our acquisition efforts are progressing smoothly in China and outside of China right now.
 We have signed the legal contract with dozens of customers. All of them are very well-known large-scale industry leaders in China and also outside of China. These customers included the largest telecom operators in -- like Indonesia and in China. The -- one of the largest utility group in China and also a couple more similar utility groups are in discussions with us for signing contracts and the leading top three automobile group in China and in Southeast Asia.
So, we are currently also have a very healthy pipeline for large-scale companies, including leading energy companies in the stage of negotiating contracts and also a very large European retail groups. They have thousand large-scale retail stores in -- across many countries in Europe. So, this kind of has all demonstrated our private cloud technologies can be implemented in many different industries, which we feel very excited that the Tuya Cube product can enable Tuya grow outside of consumer electronics industry. In the past seven years, we have been very focused on consumer electronic industries.
And we all have seen consumer electronics industry can be impacted significantly by high inflation, by the economy cycle, the consumer down cycle in China. However, many other different industries, for example, utility industries, the auto industries, and the telecom industries, they are less vulnerable and more sustainable to this kind of economy cycle. So, we believe our focus on the Tuya Cube solution which will not only provide a lot new growth field for us, but make our business in the long term, much more sustainable in a down cycle of economy. So, we will take the Tuya Cube as one of our most important strategies for the next few years.
And we believe this will bring us the new growth support for th