A weighted combination of attributes including but not limited to color, shape, pattern, brand, style, size, and material may be used to rank items when searching for similar items of a given category on an ecommerce system website. The weights on each attribute may be optimized by using feedback from users, the feedback indicating the importance of each attribute to a purchaser when searching for similar items of various categories. Alternatively, click-through patterns from the ecommerce system website can be mined and used to optimize the importance of each attribute to users by item category. The optimum attribute weights for that items category are used to rank the results in a search for similar items in that category.