If you are using the Adwords conversion counter and pulling end-of-the- month reports, make sure you run reports 30 days after the last day of the month. Otherwise, you may be missing sales and revenue.
Adwords conversion counter is a 30-day cookie and attributes a sale to the date of the click, not the date of the sale. For example, if someone clicks on an ad on May 31, but then comes back directly or through a bookmark on June 11 and purchases, Adwords attributes this conversion (and sales value) to May 31, and not June 11. So, if you run a monthly report for May on June 10, the example conversion (and sales value) is not included. Furthermore, even though the conversion happened in June, when you run your June report, the transaction won’t be there either. However, if you ran a MAY report on June 12, the conversion data would be there, since that report was run after the conversion occurred.
Always run a “look back” report to make sure click-to-sale activity that spans across two months is counted.