With ScanPower REPORT you can choose if you want to begin tracking your data from the date you subscribe or if you want to backload it by uploading or inputting historic data.  The thing that is important to keep in mind if you are a seller with FBA inventory in-stock in Seller Central who is not interested in backloading historic data, the information generated by REPORT will be slightly inaccurate until the items you had in-stock, before using REPORT,  are sold. 

In other words, our system is going to sync and bring in your current inventory - everything - and if those items do not have the cost of goods sold (COGS) associated with them (and other REPORT related information) the information displayed in REPORT will be slightly inaccurate.