Kind of. Say an ISP cuts a deal with Google to make all Google's traffic higher priority than other traffic. When customers are using less than the network's fu

Kind of. Say an ISP cuts a deal with Google to make all Google's traffic higher priority than other traffic. When customers are using less than the network's full capacity nothing changes - all traffic goes through at full line speed. But as soon as any buffer starts to fill up on any device on the ISP network (because of network congestion) the network devices will pull Google's packets from the buffer more often than other traffic until the buffer is empty. Then it's back to line speed for everything.