So community-ads are now activated, and at the time of this writing we have 4 ads meeting the criteria for being served on the sidebar:
The stats page is showing each ad's score, creation date and total/average number of clicks, but not the number of times it was served, so we don't really have a way of actually seeing our ads in the side bar, other than frantically reloading the site's front page.
And I've done that.
Then I realized, maybe the "reduced ads" privilege is interfering, so I opened up an anonymous browser window and did the same thing without being logged in.
Not once have I seen any of our community ads in the side bar.