Lets take company A, who brokers a deal on their network to dozens of publishers. The deal, for months, makes good money not only for the publishers, but for the network as well. Then, for a short time, no traffic is going to the deal really because numbers fell off, and the current promo isn't that great. We all on the same page here so far? OK
That being said, a few publishers do run traffic during the slow month during the end, lets say the last week of the month just to pump up their revenue a bit, yet, after the drop, they don't see any results. The deal in the past has done hundreds of sales per month for them, yet on this drop doesn't record one sale? Doesn't sound right.
Well, here's the sketch. What would you say if that the certain company turned off the pixel?? Publisher doing tons of sales, yet they don't show up in stats on the network side, and network calls foul and says there must be a discrepancy and the pixel is firing incorrectly, meaning all the sales you show on your end are false. Sound like something is up? Sounds like the network is trying to take advantage of residual sales, thinking no affiliates will notice or pay attention, but little do they know there was a push at the end of the month.
Keep your ears open, this scenario happenned and is still happening now.