If you have minimal Photoshop experience (or experience in any other photo and layout design program, for that matter), here’s a great little tutorial on how to create color palettes for photo layout and design.
Why would you do this as an eBay seller?
There are a number of reasons. One, better designs compel people to buy.. period. The merchandise looks better, a feel is created, and better looking product means more profit and sell-through. Two, palette contrast can bring out features of your product that you never knew were there. Color contrast highlights what’s in the photo, so there’s a chance you can completely change the look of your product (for the better) by creating different backgrounds and borders. Three, pretty is pretty. Aesthetic appeal has lots of benefits beyond just money and layout practicality. Things that are perceived as good usually are. Good design leads to positive impressions about your eBay store, brand, personality, and the quality of your products.
There’s no deception here, really. It’s just that presentation is everything. Ask any merchandising professional that creates retail displays for markets or department stores. Presentation is everything… and there’s a science to it.