google internally started working on "indexing" patent applications, materials science publications, and new computer science applications, more than 10 years ago. You the consumer / casual are starting to see the services now in a rush to consumer product placement. You must know very well that major mil around the world are racing to "index" comms intel and field data; major finance are racing to "index" transactions and build deeper profiles of many kinds. You as an Internet user are being profiled by a dozen new smaller players. arxiv is one small part of a very large sea change right now