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Customer A has five vendors, including you. You share two of the same vendors as Customer A. This is referred to as Vendor Overlap. Since Customer A is already sending to the two overlapped vendors, having them in en route will result in low ASR on those vendors. Since ASR is a key component of the PRV score, the two overlapped vendors will have a low PRV Score for Customer A, resulting in them being at the bottom of the routing order.
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