True, and the RAM memory consumed may be the same regardless of DPI, but the file size will be much smaller, hence fewer bytes to transmit and load. Now whether load times will be proportionately less or not, I don't know, since different transmissions may pre-compress the data differently.
Dale, file size in Bytes or Kilobytes has nothing to do with the DPI settings. Kikashi said it, I will explain it with more detail.
Pixel size, DPI and Inches are 3 values wich all define image size. Pixels are the size in the Computer, Inches are a real world size and DPI tells about the density the pixels are printed.
Each alone is meaningless. If you say: This computer image is in 72 dpi, I will wonder how big it is. It could be 2x2 meters, or just 1x1 inch, I dont know.
Same with the Real world size: If I assign a file to be printed at 10x10 Inches thats fine, but how many pixels it has? Has it 300x300, or only 20x20 pixels? I cant know. Or if I have a file 640x480 pixels, that says nothing about real world size.
So in order to state size in real world and size in pixels, you need 2 of these 3 values.
Pixels together with dpi gives you a fixed output size in inches.
Pixels together with inches tell you about the dpi the file must have.
And finally DPI and Inches together tell you the size in pixels the computer file will have.
So while it CAN be true that a 72dpi file is smaller on the harddisk than a 200 dpi file, it tells only half of the story!
Indeed it might be a big print, wich had been reduced from 200 dpi to 72 by reducing its pixel size. In this case, the file size in KB gets smaller.
But it also could be that one only changes the dpi value without touching pixel size, then the file size in KB will of course be the same, but the print size would change.
So, summing it up, saying that saving a file at 72 dpi reduces its size is ambiguous, and dont relates coactive to file size.
Hope thats more clear,