Wechat just added image banner ad format and an option to link to external site for advertisers targeting Wechat Official Accounts.
Tencent’s Wechat launched Wechat advertising platform in late June 2014 and started with text link ads, connecting Wechat Official Accounts with advertisers.
This update allows advertisers to use image banners of fixed width 582px and height of 166px, no bigger than 50K. Four image formats are supported including bmp, png, jpeg, jpg and gif.
In addition, the update of Wechat Ad Platform on 11 August 2014 allows advertisers to drive Wechat traffic to an external site.
To become a Wechat publisher sharing ad revenue with Public Accounts, the minimum required number of following users is 100,000.