Have a read of this clause:
"The following scenario is one that would likely be prohibited under an opt-in approach. Where a consumer visits a vendor’s web page, the vendor may be able to collect anonymous information about the consumer."
Note: anonymous information.
"The vendor may then use the anonymous information to send the potential customer an advertisement regarding their product. "
Well, in that case the information is clearly not anonymous.
"This is not the type of email that is at the heart of the spam epidemic, but it would likely fall foul of opt-in legislation. To ban these types of advertisements would leave consumers with less information and fewer choices in the marketplace, and our businesses with less opportunity to cultivate new customers."
Humm. Visit a website and get spammed? Legally as well. Guess it depends on what MS means by "send the potential customer an advertisement" but if it's email...
Sounds like it is a blanket phrase that is not tied to a specific technology. Maybe it is vague to cover targetted adverts on the web page too?