A WeChat Official Account does not allow you to send promotional messages to your followers on a regular basis. However, WeChat does allow service accounts to broadcast 4 promotional messages to its followers per month.
With the Conversation API, it’s possible to send messages with promotional content during a reply to a message or when followers click on the custom chat menu or at the time when they start to follow Official Account.
Refer to the table below for further details:
| Action by WeChat user | Sends a message to your WeChat Official Account | Clicks on bottom menu | Subscribes to your channel | 
| Number of replies a business can send | 20 Resets when a user replies | 3 | 3 | 
| How long after user action | 48 hours | 1 minute | 1 minute |