As a product or technology, it is best to have a patent application number that others can find, so as to facilitate others to understand your things and help you with your transactions. There are patent trading platforms in many places on the Internet, such as the Baiteng Technology Mall mentioned upstairs. In addition, in big cities such as Beijing and Shanghai, similar websites also have patent trading platforms similar to intellectual property service centers. You can go to the websites of intellectual property offices in various cities, and you can usually find relevant links. For example, on the website of Shanghai Intellectual Property Office, there are links such as "Shanghai Intellectual Property Information Platform" and "Shanghai Patent Trading Network".
It should be said that many cities have similar platforms, but the effect is hard to say. After all, only a few people need to buy technology, but many people think they have good technology to sell.