Affiliate Marketing Ethics
Do Not Abuse The Trust - Your potential as an affiliate marketer lies in the trust you have with your readership, it is imperative that you don't ever do anything to compromise that trust. Without it, not only will you not be able to refer any of your readers (and make a commission), but you will end up losing them, and the community that they make up.
All this, of course, brings up the questions. How do you ethically promote a product (as an affiliate marketer) on your blog? Well, you do it simply by disclosing that you are promoting the product.
As a blogger, the best way to (literally) capitalize on the trust that you have [carefully and professionally] established with your readers is in your posts [of quality content and not nonsense babble]. After all, having a trust-based relationship with your readers does not make them any less banner blind.
Professional Strategic Subtle Product Placement
The real power of an affiliate blogger is in the (ongoing) conversation they have with their readers. It is here that they can generate the word of mouth buzz that converts into actual sales that they can subsequently make a commission off of.
Of course, when you start to insert product promotions in your post, you wade into the area of product placement. Because your readers are in a certain mindset when they are visiting your blog, you have to be [professional] and mindful where you place mention of product throughout your post.
So how do you handle product placement in a way that protects the authenticity of your blog and your voice -- not to mention the trust you have with your readers? Here are a few tips.
Disclosure Page
Set up a disclosure page and link to it at the end of each post. Make sure to keep that page up to date with all the affiliate programs you belong to or have belonged to in the past. Even though you may have left an affiliate program a year ago, the posts you wrote at the time will still get hit with organic traffic, so you have to let new readers know that at the time you had a relationship with the vendor.
Be Straight Forward
Let readers know right off the bat that you are an affiliate of the product/service in question. Your readers are smart people who can exercise their own judgment, and they will appreciate that transparency. Besides, the fact that they are one of your readers means that they already trust you, so if you say that something is good, they will probably still be more likely to trust you than not, even though you told them that you are promoting it.
Keep It Real 
Just because you are promoting a certain brand or line of products, that does not mean that you should be a full-time salesman for them. After all, you built a reputation and a community as a blogger. Don't post only about the product(s) you are promoting. Give review blog posts on other products, services, tools. This does not mean to fill your blog page with a lot of spam. Keep it professional blog posts. Find out about products and services or internet tools that interest your readers and give some reviews to help them out. This is part of relationship building with your readership and network. You can find out what your readership is interested in through the comments they leave on your professional business blog. Always interact with your readership through the comments. This does not mean you have to answer every single comment, but be interactive. And don't be afraid to give certain products negative reviews. Be honest in your reviews. It might seem like a waste of time because it won't convert to a sale, but it will actually bolster your credibility for when you actually give something postitive to review. Basically, call things as they are and let your readers know that you are still looking out for their best (niche) interests -- and not just trying to make a profit off of them.
