MSN Adcenter's 6 minute survey pulled 7 minutes later

I received the following email from MSN Adcenter at 2:05 PM today:

Microsoft would like to invite you to participate in a short survey about Microsoft® adCenter.
This survey is easy to fill out and should take no more than 6 minutes of your time. Plus, when you complete the survey, you will be e-mailed a gift certificate to amazon.com worth $10.
To access the survey, simply visit the URL below, or copy and paste the address into your browser:
http://survey.sotech.com/195008/start.asp?s=1
We sincerely value your opinions and look forward to your participation.

At 4:30PM I followed the link and got this:

Thank you for your interest in this study; however, this survey is now closed. We appreciate your willingness to share your opinions with us and hope that you will participate in future surveys.

C’mon now MSN – that’s a sure fire way to piss off a lot of your subscribers, some of whom are already pretty annoyed with you.