Hi - Research shows that most people use search, rather than browsing categories, to arrive at your listing. And that most people search by title only, relatively few by title AND description. So the title is really where you need to concentrate on having the keywords that people will be using to search with. Thinking like a buyer, looking at other's listings, and common sense will probably tell you what to use. And you are right, keyword spamming in its various forms is a no-no. With the exception of adequate pictures, including gallery pics, very few of the listing upgrades are really considered to be cost effective.
This advice is pretty basic, applying only to listings, and doesn't really cover getting your web site high up in Google's search results, or any other advanced strategies, which is another phase of this topic altogether. I would like to see other members add to this thread as their experience would be valuable to all.
