1, Online Education Platform: At present, there are many online education platforms on the market, such as Netease Cloud Classroom, Tencent Classroom, Massive Open Online Course Network, etc. There are many signed teaching video tutorials available for purchase on these platforms.
2. E-commerce platform: On Taobao, JD.COM and other e-commerce platforms, you can also search for many sales pages of signed teaching video tutorials. Price and quality are uneven, so we need to pay attention to selection.