@sketchyarchitect said:
hey you probably already know this and it may not help you, but you can compress the size of a sketchup model by copying everything in your sketchup file (ctrl a) and pasting it in a new sketchup file.then save the file. you'll notice the decrease. Depending on file size this can reduce the size to a tenth of what it was.
that sounds like a weird round about way to purge your model (basically, gets rid of all unused materials,component instances, etc)..
window-> model info-> statistics -> purge unused