Know when to wait. Some affiliate programs require a certain level of traffic, subscribers, etc. If that’s the case, I say it’s better to wait to apply for that program instead of applying and hoping for the best. You risk being labelled the person who can’t follow guidelines and you might also risk not be allowed into the program when you do meet the qualifications.
This domain can work for people in two ways. One is to get sudden bursts of income by selling a certain product. The second part is selling a service that gives you recurring fees. This course on Affiliate Marketing Strategy for Stable and Recurring Income can be very helpful if your objective is the latter. At 5.5 hours and 56 lectures, this is very extensive and useful for those looking at mastering this subject. Details are available here.
Another thing to consider is that even if you break even on the first sale, you're still winning. All you need to do is create more content about other problems that target market may have following the same principle and queue them one after the other. For example if we target women that want to lose weight they may also have wrinkle problems, digestion problems, diabetes, aging problems etc. We can easily create a chain of issues we run the email list through, let them opt in for what matches their issues and make several sales to that audience.
When promoting affiliate offers, just make sure you are fully aware of all the terms and conditions attached to your affiliate program. Some programs can be strict about how they allow you to promote their products. For example, some may limit you to banner ads and links only, while others will allow you to use paid advertising, but won't allow email marketing.