I'm not sure, I just think that there is too much empty space. The letters of the actual written content could be a little bigger if the blank space was reduced.

So, can't you set up your own cookies on users when redirecting them, so you can filter later?

Ok, but really keep up with the Google Analytics approach and try to make data presentation better. If you manage to find out a way to do it without GA than it will be a different service, which you could run in parallel.