As of today, Madoka has usurped Haruhi as the top anime copyright tag on Danbooru. It really is awe-inspiring to see little seven-month old Madoka surpass a juggernaut like Haruhi with five years of history behind it. One goddess toppling another is a beautiful sight.
If the numbers is in the system, it can be tracked.
Interesting though that comparing with the current reigning champion (Touhou, 12× Madoka) had roughly 11% comic content, while Madoka had about 21% comic content. By the way, Haruhi tag had about 9% comic content.
PS: only checked the number with "touhou -comic" and "mahou_shoujo_madoka_magica -comic" tag search. Not sure of the validity. Feel free to give correction :)
That much I can believe. I may not like this series but I'll definitely grant that it produces a lot of good doujin material. Aotori and the good end revisions are half the reason the series tag isn't on my blacklist.