According to this statement:
September update: Community Ads are now live network-wide. All ads with a score of 6 or higher, or with a score of 4 or higher and no downvotes will be displayed (except for any that have a note from the CM Team explaining why it wasn't selected).
Community Ads are live.
But I can see no Community Ads in https://askubuntu.com. I have also asked fellow users about this, and they too cannot see the ads.
All I could see were these: