This is, in my opinion, shortsighted. It's straightforward to create ads that you can't block on the client so long as you are the server of the ads yourself, as Google is. I'm not going to detail how since I don't want anyone on HN to get any ideas and build a business of it, but I'm sure it will happen eventually. For the time being I suspect it's cheaper to keep the current tech running since it brings in enough revenue, but if that ever stops being the case, I expect things not to end well for people who don't like ads. Google search is a good example of this, ads are literally intertwined into the search results, if you take this a few steps further you have ads that you literally can't block on the client.