I have one forum which has a low eCPM eg 29,284 36 0.12% $0.65 AU$18.97 (about 50 cents per click) Where as other sites of mine have a high CTR and eCPM eg 5,546 148 2.67% $17.41 AU$96.55 I understand that its all about content and key words but is there anything that I can do to improve eCPM?
lol but I meant should I change key words etc on the site to improve the ads being shown? Would that help or not?
Yes changing the keywords will help you.select good keywords then promote those.you can find the good result.
Your forum are having low eCPM due to the low CTR (eCPM basically is depend on both CTR and CPC) And forum normally are having lower CTR compare to website If you can improve your forum CTR, the eCPM will increase