I get a very low click count with this site (<1%) I've tried several different placements. Just wondering if it is the subject (Webmasters are notoriously low clickers) or I need to mix the colors up some. It get decent traffic about 500 per day. I know I need to redo the design of the site, but that doesn't seem to be a problem, most of the traffic views multiple pages. http://www.topwebsitetips.com
First of all the placement is good but you have not mixed it properly with the background. Make the background of ads white and remove curved sides.
I've tried that too, a version of that is on this page http://www.topwebsitetips.com/FreeLinks-Directories.aspx The left side seems to get a little better ratio, but not much