Earlier quoted context omitted.
I don't think that's an accurate way to portray it. I might be able to afford $5/month, but I'd rather buy five songs a month with that money. Ad-free Web viewing is a luxury, not a necessity. Also, not all advertising targets disposable income. I might see an ad for clothing, which I would need to buy at some point. Maybe I'm underwater on my mortgage and want to learn one weird tip to get refinanced. Plenty of ads…
Ad-free Web viewing is a luxury, not a necessity. Given the prevalence of ads as a malware/privacy invasion vector, I'm not sure that's true anymore. Browsing the wider internet without a blocker on is like walking down a bad part of town and sticking yourself with every discarded needle you find.
Sure, the NSA might find out what web sites I've been visiting, but that's a really abstract concept for most people. I don't want to attack your analogy too much, but sticking yourself with discarded needles is a much more tangible risk, and doesn't bring any benefits along with it.
There are some sites I frequent that are egregious about ads, but they provide enough value to me that I keep going back.