Sponsor is perhaps a strong word. You need another WeChat user to verify your account by scanning a QR code displayed on your app using their app. You need to do this when you create an account, and also if you haven't used your account in a while. I assume this is some sort of anti-spam/anti-bot feature.
Note that the above is just for the chat feature. You have to jump through more hoops if you want to make payments using the app.
Note that the above is just for the chat feature. You have to jump through more hoops if you want to make payments using the app.