You only had to answer it once or twice a year, but you had to answer it to get in. Now, we have self-submitted information that can be used to help sites sell advertising that targets the customer. Yes, I know it would be a pain in the yazoo twice a year, but a greater piece of your privacy might be protected and you'd know who has information regarding your Web habits. I also know some would fill in bogus information. I've done a ton of surveys in my academic research, and bogus information is part of the process.
Most respondents actually do fill in good information.
Yes, the information gathered might be sold around the Web, but remember that it's general information. It's not specifically you. It's information about an audience en masse. That's a great deal like the method used by the traditional media. No, this isn't a perfect idea, but think about it.