Is there any way to increase the number of interest based ads being served via AdSense? As a percentage, interest based ads have been declining for me the past 2 months for me which is not good news because for me they significantly outperform contextual and placement ads. CTR is exactly the same as contextual, but the CPC's are MUCH higher. Last year, interest based ads were about 25% of all clicks, but that % has been more like 10-15% the past 2 months. I'm trying to figure out why they would be down? I've moved more towards text based ads, perhaps interest based ads are more image/rich media heavy?