I like to use banner advertising for my blogs for a couple of reasons. First reason is the companies I am affiliated with send emails when they are having a special sale with large price discounts so banner advertising when special sales are happening can be very productive in generating sales and commissions. The other reason I use banner advertising is I can use colorful eye catching banners that naturally draw the blog reader's attention. I do not use the large banners as I feel they are to imposing so I stick with the smaller banners and this has worked well for my blogs. I am aware many Internet gurus will tell you not to use banner advertising due to the fact most search engine spiders do not like sites full of banners, and many visitors to your blog or website will get the impression all you want to do is sell them something. Which you do, but you want to do so in a way the visitor reacts to unconsiously, not by shoving a bunch of rotating, blinking banners in their face. Use banners, but keep it subtle, and you will notice a nice increase in sales.