edit: Especially since now I look at the site, it appears from the user's point of view that they could go through the entire donation process without ever knowing that mydunktank is taking nine percent. I had to click through to the "terms and conditions" and read term 1(b)(iii) to find any reference to the fees at all.
It even tells me "I understand that my money will be donated to (say) The Spina Bifida Resource Network even if this dare doesn't win.", when it should say "I understand that 91% of my money will be donated to The Spina Bifida Resource Network..."