Not a top secret. But maybe a bit hard to find.

APSense has a feature called "User Ads". These ads look similar as the paid ads you see on the live feed and may other place: a little graphic and a few lines of text.

The difference (besides being a paid option or free) is that the paid ads are getting the most exposure on APSense. User ads are shown on your own pages: your APSense profile and articles and rev pages you have written.

However they only show when you are upgraded (remember you get 1 months upgrade free if you refer 5 people to APSense). If you don't manage to refer 5 one month, don't worry; the ads will stay in your account and show automatically again once you are upgraded again.

To find out easy ways to get referrals in APSense read my article "How to earn from APSense".

Especially if you post own content regularly it is worth the time setting them up. So where to find this feature?

Click on link "create an ad" next to Sponsored. Than you are directed to the page to submit a paid ad (costs $10 a week which is not expensive for a site with 180K members). Now on this page you can see a menu on the left with the option "user ads". That is the one you need to submit your free user ads.
Note: you can only submit them when you are upgraded. But like I said, once posted they remain in the system and they will show automatically again the moment you are upgraded, either by subscription or earned but referring 5 in one month.

What ads should you choose? It is the best to create ads that are related to your content.