In or Near Content
I find that the most effective position for most ads is actually inside or very close to the main content of your page. If the middle section of your page is where an article or posts is - the best spot (in terms of conversion ) to put an advertisement is in the middle section. Of course this may compromise your design or clutter your site - depending up the goals of your site you may not wish to do this - however in general the closer you have the eMiniMalls to where your readers eyes will be (content) the more chance they have of seeing and responding to them. A great way to get eMiniMalls inside posts is to use one of the plugins that are appearing for blog platforms (see section below).