[pjscott]

This doesn't fit as well in a blurb, but a more precisely-stated version of Thiel's thesis is that, since truly competitive markets tend to drive down profit margins, you want to have some big advantage that's hard for competitors to duplicate. MS-DOS's big, hard-to-duplicate advantage was the IBM PC, and Google's advantage is that their search engine was just so much better than others in the early days -- it had a much better ranking algorithm and didn't bloat up its pages trying to be a "portal". For another example, consider Facebook: its advantage is that approximately everybody's friends are on Facebook, and not on, say, Google Plus.

Does that sound more reasonable?