Is is sharp or is it soft?
This is my BIG pet peeve! Focus, focus, focus. Let's start by saying, I can not stand people who put up photos for sale that are out of focus! It is unprofessional and wrong. If you are a professional, then do a professional job. I like to say that every photo that comes out of my camera is not a nugget of gold - I am not perfect - but, you will not see blurry photos for sale on my site!
Now let's talk about "soft". WAY too many people also put these up for sale. There are varying degrees of soft photos, but too many people put up images that are way too close to that border of soft and/or blurry. A soft photo simply means you have missed the focus by just a bit. Maybe the foot is in focus, or the collar, or the toy - but shooting for the eyes is the best possible image.
The image to the right was NOT for sale. The actual focus on it is just behind the ear on the hair at the back of the neck. To see this image larger, you would really notice that they eyes or face have missed just slightly. Be picky!! It's your money!! Don't just buy a "cute" image from someone - make it be a good image too!Check out image samples here.