There is much disagreement over affiliate marketing on the internet - the idea of advertising masquerading as content is a contentious one. Many principled people balk at the idea of placing ads on their internet boards - and certainly for your main content - your "shop window" this isn't really such a great idea as it tends to give off a bad impression. This is why, if you're going to go down the road of placing adverts on your blog you need to consider this quite carefully.