careful about this slippery slope ... it's rare for something to be 'very original'. PageRank is based on well-known academic research by Jon Kleinberg and others on graph reputation algorithms ... of course, the application to web search and wonderful execution was what made Google's start possible. You could argue that MS, Facebook, Apple, etc. also innovated greatly on existing technologies and created something 'very original'.
In addition there's long standing research in the field of Library Science about the importance of citations. It seems like a natural progression from judging the quality of a paper by the number and quality of papers citing it, to PageRank.
i totally agree ... if larry page hadn't been in a Ph.D. program, he would've likely not gotten exposed to that sort of research, especially because back in the early 1990's, it was much harder for people to get access to or even knowledge about research papers (you couldn't just, ummm, Google for them!)
careful about this slippery slope ... it's rare for something to be 'very original'. PageRank is based on well-known academic research by Jon Kleinberg and others on graph reputation algorithms ... of course, the application to web search and wonderful execution was what made Google's start possible. You could argue that MS, Facebook, Apple, etc. also innovated greatly on existing technologies and created something 'very original'.