Activating your account

I had another cleanup in our user list today and deleted 4 users. If you don't activate your account within 7 days after it was created it will be deleted. Im not sure why people don't activate their accounts but I guess it might be because they have given the wrong e-mail or something. We're still about 25 users from our target of 100. Hopefully we will reach the target in September. I really want to give away those t-shirts.