Online vs. Offline Advertising

In this article, online vs. offline advertising, they look at the pros and cons of internet advertising. One item of interest they look at is the instant knowledge they gain about their visitors. They know where they are coming from, what they read on the web site, and how long they were there. This article suggests that online advertising can be very focused on their target markets. What do you think? Do you put more stock in what you see on the television or what pops up in your email? The online advertising maybe more focused, but could it also be more intrusive?