Offtopic, but Google's propensity to migrate anything popular to their own hosted content is a better example of this. They find ways to present the good stuff without the end user ever visiting your site. At some point, this starves off the sources.
"That's some nice data you go there, guys. It'd be a shame if... somebody scraped it and kept that page view and ad revenue for themselves."
Again ironically, this will put Google out of business if they keep it up, unless they can start to collect all that data on their own or otherwise incentivize content producers to allow them access.
Offtopic, but Google's propensity to migrate anything popular to their own hosted content is a better example of this. They find ways to present the good stuff without the end user ever visiting your site. At some point, this starves off the sources.