Every time I try to increase the CTR, my eCPM plummets. Therefore, I do not try to increase the CTR anymore. Better to have a high eCPM then a high CTR in my opinion.
Agreed. Everytime I try and tweak something due to greed, I always end up shooting myself in the foot. It's always best to let your ads and traffic for that matter take on a natural course of action. Instead of worrying about increasing your CTR, I would focus on getting better themed ads that pay more, this way you can keep your current traffic, but increase revenue, which was probably your overal goal anyhow.