How can they know my blood type?? (these quizzes are way too scary!)

Ok, this is a bit spooky... I tried this quiz and somehow it could even guess my blood type! Let me know if this also works for any of you guys!!

Your Inner Blood Type is Type A

You seem cool and collected, though a bit shy. You are highly driven and a perfectionist, but that's a side you keep to yourself. Creative and artistic, you are a very unique person who doesn't quite fit in. People accept you more than you realize, seeing you as trustworthy and loyal. You are most compatible with: A and AB Famous Type A's: Britney Spears and Hilter

What's Your Inner Blood Type?