1. The fees can be collected on transfers which occur between two members of the network without funds leaving the wallet. That's clearly the long-term goal of any network -- to grow to the point where everybody is on it.
2. The stated goal of ChangeTip, as seen in their videos and materials, is to replace advertising and other indirect ways of monetizing content with a way to directly express support for creators.
Advertising is a model whereby content creators get vanishingly small amounts of money for views, while having to place their content next to third-party claims and pitches which they do not endorse. Historically this has been because the rates on payment processing have dwarfed the actual value that a single article or video view delivers to a single consumer, so asking for half a penny was not feasible. You can express that level of support with BTC however.