I actually find this slide deck not too clear. Perhaps some information was lost without the actual presentation. One problem I see with a lot of ideas behind game mechanics is that people still don't have a good grasp of how the work in non gaming contexts. Mechanics such ass collections, points, and feedback are mentioned - but I've seen eBay's seller feedback rating referred to as examples of all 3 of those over various slide decks.
It's an interesting space, but still very, very immature.