Top contributor Will Stape talks about Diplay-only articles in the following article and why there is a lot of value in this "free" work.
Before I provide the link, though, I want to reiterate that while this is a good option (I should know because some of my biggest paid months have been when I've just published DO articles), you shouldn't also dismiss upfront payments just because it seems hard to figure out. Getting declined? Then head to the forum and place it in the Workshop where experienced contributors can tell you why.
While I don't always have time to write on AC as much as I'd like to, I still see the value of utilizing both the DO side and the upfront side of AC. Don't stop because you may be getting frustrated with it. Doing so will hurt the amount of money you could make.
If you want to read more about the "upfront" topic, look in the right column at the label cloud at the top and click on the word "upfront" to see more posts.
Profit Power of Writing 'Display Only' on Associated Content
Don't like giving it away? Hate the idea of dealing in freebies? Does the thought of publishing display only give you the chills? Here's why you shouldn't hate nor fear the 'free' on Associated Content.