Currently I'm using free SMF ( Simple Machine Forum ) software and online user normally 120 ppl daily. Using Adsense since last year, and have tested many variations. My research shows that - user don't like contrast banner color - 2 leader board on the top + blended + removed border is the best - they like to click banner placed in the header rather in footer - put 3 banner will slow down the forum loading - ad link between topics receive few click - clear the area between banner, so they receive a breathing space..and user will click - rotate the banner using soft color - don't use border, try to blend with forum color. - using the standard Google Earth theme is the best ( remove the border and use white background color + leader board ) - remove the PSA by using alternate ad - leaderboard received much of teh attention ( place in the middle of the forum ) - modify/hack the topic link by acnhor it to your adsense ( showtopic.php?id=45566#adsense ) - there's nothing to do to improve CTR ....