Unfortunately, the one site who claims to do it is totally out of line and the sales numbers absolutely meaningless.
For example, I have been a GOLD Powerseller for years (over US$10,000 monthly sales). According to that site, while I rank #117 in Canada (by feedback rating) my monthly sales would be only $1,528 (that would hardly pay my monthly fees, let alone the cost of goods and make a profit), have 491 listings (I have over 2,500) with only 39 successful, etc....
I have no idea how they calculate their numbers but they are obviously way out. :-(
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