It is a very good idea to use different product promotion strategies so you can figure out what is working and what is not. Try to do split testing and measure the performance of each campaign then take actions accordingly. Changing a few things here and there can increase your profit dramatically. Make sure to place the banner ads on different areas of your site’s pages. Some positions will make the ads more noticeable than others.
For example, if I talk about how cool a product is, and then you find out that I’m an affiliate for them, wouldn’t you as a conscientious observer become skeptical as to whether my information is biased, if perhaps I’m only saying how cool something is because I can get paid for it? Wouldn’t that make you question my integrity with other things I say as well?