I just tried this week the pop-up adverts from both Juicy and Plugrush. Turns out that I gain more from plugrush, which pays more on non-US/UK or the usual low tier countries where significant amount of traffic I have are from. But I noticed this, JuicyAds pay more on the tier-1 countries than plugrush, so I think JuicyAds popup adverts are best on sites with mostly tier-1 geo traffic.