I don't normally mind adverts on the web, as long as they aren't pop-ups or pop-overs, because I'm good at ignoring them. Some of that is because I tend to use add-ons to Firefox that remove them or require permission for flash to work or stuff, and some of it is because I'm generally fairly good at visual filtering after the initial distraction.
I tend to figure that if sites make money from adverts, that's fine, because it's essentially getting the people stupid enough to click on the adverts to pay for everyone else to use it. Kind of like the National Lottery functioning as a tax on greed. And yes, I know that wasn't what it claimed to be when it was set up. Sometimes the adverts are even for things that are useful or interesting, rather than playing games to dress up fake dolls which probably charge you for the privilege.
But then this page argues that adverts selectively target the poor and so on, which really got me thinking. What does it mean for me to love people who are greedy and stupid enough to play the lottery? What does it mean for me to love the kind of people who buy so much stuff via internet ads that they make the ads worthwhile? Should a Christian approach be to remove them from harm, or should it be to leave them to get harmed, then help them recover in the hope that they will learn? I'm honestly not sure now.