Let Me Explain:
You just have to paste sales numbers and change the date on DATA sheet. This would bring raw data into a presentable report in the next spreadsheet. Through formulas and links, the sales information than forms into comparison with last month sales numbers. (ProAnalysis)
The numbers would further go ahead and constitute comparison with current month last year to ascertain the performance as compare to last year (PeriodAnalysis)
You would also get Top5 products of each month to discover you Top5 products. It will help you ascertain the most viable and profit making products.