Sorry vidi, I thought I had responded to your last post already. but Yung is exactly right. Look at that pic again:
<img src="http://atomicrobotdesign.com/blog_media/sprite_movement/images/gb_walk.png" border="0" />
now this isn't completely scientific, but on disk that image takes up 168k. The next image is a rough example of the size of a cut up version of the character. If you made the images specifically for spriter, they would be in separate files, so you wouldn't even need to have that waster in between space.
<img src="http://dl.dropbox.com/u/1013446/Spriter%20Releases/spritered.png" border="0" />this image takes up 12k. I'm not sure how directly the disk space translates to VRAM space, but it should be a similar ratio.
There is some white space in the large version, but if you were to fill it with images, you'd have 18 frames worth of space. This means a sprite would use about 14 times as much vram, just to have 18 frames of animation, for this particular character. Want 36 frames, then the regular sprite would use about 28 times the space as the spriter version. The spriter version would still take up 12k of VRAM, even if you had a total of 1,000 frames. This will help not only VRAM usage, but eventually download size as well.