Basically, we have no control of the ads that come through Google or Double-ad. They seem to be generated at random and by a mechanism that suits Google, etc.
Also there appears to be some connection with the IP-address of the user (I happen to get more Dutch ads on some American sites - although not here).
Every now and then one or more of the ads we're getting annoys us and/or our members. This used to be on the previous platform as well. An example would be ads for bootleg DVDs. Whenever they were signaled, Parker would add them to a filter as well as notify the company providing it (not the original one, but Google, etc.).
I suppose the same is still going on now. Perhaps some changes because the contract may not be the same as we had, or perhaps we use different filters now, or else they changed URLs too "smartly" (that's what these firms do indeed) or there just happen to be a few new ones.
No mystery there: indeed we cannot know beforehand exactly what we will be receiving. Indeed we are not thankful for everything we're about to receive. And indeed we like to get URL's if possilble, so we can block irritating offenders.
That's mostly all to it!

Also, as you'll understand, there's content that we rejected beforehand.
(My wicked punny side was inclined to write a typo in the word 'content', but I promise I won't do it.)
(But keep those links coming folks, I'm inclined to say!)
Cees