Question for Freight Brokers

Just something I'm curious about. When you book a load on behalf of your client the shipper, on average when and how does the shipper pay you? Do you invoice them when the load is booked and wait for a check to arrive in the mail, or do you have shippers that pay you either when the load is picked up, or when it is delivered? Also, do most pay by check or do they pay by ACH or other means? What happens if the shipper pays when the load is picked up and additional charges occur after the fact like detention pay?

I can see some of the large brokerages requiring payment when the load is picked up as a condition of doing business with them.

 

Which means when you do quick pay you are actually fronting the money to the carrier before you get paid. I had a feeling it worked that way, but I wasn't sure. Thanks for the info.