Networks who don't pay affiliates cause merchant not paid

Yo yo affiliate bitches what gets my goat is networks who don't pay because merchants have not paid.
I understand that a network is in business too, and they will not want to funding payments for merchants indefinitely.

However some of the merchants who have not paid me are blue chip companies, with multi million turnovers.
Why can't networks account payable departments collect this money on time? why does it take so long to invoice.

Thing is when other networks can pay affiliates in a timely fashion it shows these networks up. The Google Affiliate Network is going to shake a few feathers too.