I have used ShareASale, and Commission Junction. However, in order to succeed with any type of affiliate offer you can not simply put up the products and expect to earn cash over night. Despite what some still say, working with any type of affiliate program will take other steps in order to reach success on any level.
(1) You need to research the niche- this goes hand in hand with then determining better what products to promote.
(2) Drive traffic to the offer by using social media, blogs, rss feeds, and videos explaining what the customer can get from using the product. ( this step is not limited just to these few mentioned either)
(3) Always be building a list ( to promote to them over and over again ) learned that lesson here on this forum.
(4) Determine your marketing approach, and plan for it on a daily bases. learned that part here too.
(5) Build backlinks for promoting products ( depends on how you set up your pages to start with)
These are simply a few guidelines to what needs to be done, in addtion before selecting the affiliate product.
All of these things are very doable, but you must keep in mind that this is work, that may not always pay off when completed. However taking a step back, and planing your approach ahead of time can often help to avoid having a lot of "none Paydays"
I wish someone would have been there to say and explain some of these steps to me when I first got started on this path,
I hope my answer helps you Aesom, and also can help all who may read this topic.