Make sure you are offering a product others want to purchase at a competitive price. You can do your own research regarding competitive pricing or use software that assist with the detail research. Your question does not note what types of product you are selling; however, most product sells are seasonal and that may be causing the dip you are experiencing. Compare the results to the same week last year and the year before and review trends. I work with clients that sell products on line - feel free to set up a call if I can assist further.