Banners don't convert well regardless of how targeted the audience seeing them is.
A quote on banners:
For example remember those marketing tools called "banner" that use to drive sales at an astronomical rate a few years ago? Well those banners developed a term called "banner blindness." That means most online viewers will not click on banners even if they do pertain to what they are looking for.
full article here: http://marketing.about.com/cs/internetb ... ecrets.htm
From what I have seen, experts across the board are in agreement on this topic.