Earlier quoted context omitted.
Count all of the web content you've consumed and all the web services you've used in the past year. Now count all the ones you've paid for. Also, those paid-for services you mention are of such high quality (to you, not advertisers) because you pay for them. You are the customer not the product, as they say.
Most people don't pay for Wikipedia, how are they the product? Many people pay for Hulu and many other services, and still get ads, how are they not the product? That cliché can't die soon enough.
Hulu is an example which mixes both approaches - clearly an $8/mo premium subscription isn't enough to support their business model, so it has to be supplemented with ads. Not sure why this needs explaining. TV is obviously an industry very tightly coupled with ads, making it more difficult to disrupt with a fully ad-free approach.