Operation Fabulous hasn't been updated for years, their way of listing publisher sites is terrible and they have a high minimum withdrawal amount (0.05 BTC) which discourages smaller sites from using it.

BitAds is also better in my opinion because the ad views are shared proportionally as opposed to Operation Fabulous where only the ad of the highest bidder is displayed.

Hopefully the admin either comes back or someone else creates a site with a similar feature set.