I don’t recall exactly when I started displaying ads to non-members only, but it was pretty-early on. I saw this as a way to encourage members to sign-up and keep coming back by making the site less ‘spammy’ looking for members.
Of course the immediate drawback of showing ads to non-members only is that the more people that sign up, the less potential Adsense/Kontera earnings you make. I’ve balanced this by offering Premium Memberships which is now my best earner.

Thanks for the insightful and informative reply, Randy. Gave me ideas re what to do with my sites. I had a cursory glance at your ‘Premium Memberships’ post before, but will now study it more carefully — might just pick up some things to implement on my sites. God bless and Happy Holidays!

Hi Dino;
I only display Kontera to non-members/anonymous visitors, so my members don’t complain at all . it’s the same with Adsense.. 99% of Adsense is shown only to non-members.

Oh I didn’t know that re AdSense and Kontera. Has this been your policy from the start not to display ads to members, or only when you started getting high traffic? (Can’t remember now if you mentioned this in your ebook which was a great gift this Christmas by the way. — You’re an inspiration, in particular for Drupal users like me. Thanks for the prompt reply and keep up the great work! )