Of course, optimizing the number of bytes transferred is important. You may expect that optimizing network usage just means minimizing the number of bytes transferred. Things like, don’t send a multi megabyte image to a phone when it’s only going to be rendered at a small pixel size. That’s certainly part of it, but there’s other things at play, too. And in the end, all of these things are important. How often we send requests needs to be optimized for the latency of the particular cellular network, and we have to be careful about the power consumption, as well. Although it’s less important now, we do still need to optimize for the maximum allowed TCP connections.