Building connections in your niche is essential. Once you know people posting similar content you can work with them to write guests posts on their blog. This is a great way to get backlinks since you'll be writing the content on their blog. If you have a huge article about the "best kettlebell for beginners" for example you could guest post for people in the health niche with kettlebell exercise tips.
You should also make sure you aren't competing with your own affiliates for eyeballs. Any marketing channels you're using, such as search engines, content sites or e-mail lists, should be off limits to your affiliates. Put marketing restrictions into your affiliate agreement and notify partners immediately. It's your program--you set the rules. Or, if you prefer, you can let your affiliates run the majority of your internet marketing.