A great feature of Chitika eMiniMalls is that you can use an unlimited number on your web page. While we certainly don't recommend plastering your page with hundreds of eMiniMalls, we have found that using up to 3 of the ad units on your page can be effective, especially if they are targeted differently.
Here is a nice example of this:

The publisher put a 468 x 180 “Blog Banner” right underneath his post, and targeted it using the post title as the keyword. However, he also stuck a 180 x 150 “Small Square” under the sidebar on the left. In this eMiniMall, he uses lateral targeting by choosing the iPod as his keyword (because he feels that his audience is likely to be interested in them). Using multiple eMiniMalls units is a productive way to reach your audience on several different levels.
Another cool thing you can do when using multiple ad units is to use the “channel” feature so that you can track each unit separately. That will tell you exactly how each unit is performing. You can read more about this feature here.

