And my livelihood had nothing to do with ads.
Most companies seems to advertise online, because the competitors do and you can't prove that they don't work. A large number of advertising sponsored sites would have to reevaluate their business model, if the people moving physical goods decide that ad-networks aren't worth the money. Sadly the only alternative seems to be some sort of micro-payments, which have yet to materialize.
Online ads, including targeted ads, isn't something I have much faith in. I have yet to see it work, outside search engines.
edits: (1) However, its only recently that theres been this major discussion about ad blockers, and perhaps those who are not opposed to them are either changing their view, or are keeping silent as the majority opinion against ads is currently dominating the discussion.
Google's cloud computing service and especially Google Apps already bring in monies.