Hi, currently, my site is running some free ad banners for two companies. Can you guys help me to evaluate these banners? I want them to be successful so that advertisers will drop money on my site.

Go to this page: http://www.usbworkshop.com/news/
Look at the banner on the right hand side (150x800)

Please gimme some suggestions on how to improve the click-through results. Right now, the "ThumbDrive" ad is getting 4.24% and the "MP3" ad is getting 4.36% but the "InsideOut" ad is only receiving 1.80%.
I really want to know why the performance varies so much.