She has a great article about self-publishing and book covers, titled "Image Desperation: The Kiss of Death for Independent Publishers," and it's a timely post.
The Kindleboards Writers' Cafe is awash with threads about covers. Spend hundreds or DIY? Spend $50 for basic image manipulation? Is this cover good? How awesome is my cover? No on should ever, EVAH spend more than $75 on a cover. No, a hand-illustrated cover is worth $500-$1,000...
And so on. Cathi makes some great points, but I love this section:
Another big mistake is the cliché image. Using chess pieces on books about business strategies has been done — to death! One book production company recently published a book that not only used the old chess cliché, it actually had the pawn featured on the book cover. Whose goal is to be a pawn? Other overused cliché’s that smaller presses can’t seem to let go of include puzzle pieces, people shaking hands and locks and keys. Unless you’ve thought of a completely fresh way to use these elements, come up with another idea. They have simply been used too often.
But cliches are a step above "image desperation":
That’s when a novice publisher is so desperate to have an image, any image, that he or she will “make do” with completely unsuitable photos or amateur illustrations that virtually shout, “self-published.” Sometimes the publisher simply doesn’t have the “eye” that can discern a good image from a bad one; Sometimes he or she does not understand what the image should be; Sometimes it’s a budgeting issue. No matter the reason, it’s not only unacceptable, it’s completely unnecessary. It costs just as much to produce a bad book cover as it does to produce a good book cover.
I have the art skills of a 5 year old with olive oil smeared in his eyes, so I chose to hire a professional to handle my cover. The Dunning-Kruger effect is alive and well for some indie publishers; people often overestimate their graphic design/book cover design skills, then wonder why their book isn't selling well.
While there are many reasons, outside the cover, why a book might not sell, eliminating a poor cover as an obstacle is critical for success. Don't fall into the "image desperation" trap.