Like a number of others, Zetta Research, LLC in San Mateo, CA buys patents from failed startups, but instead of just hoarding the patents, it works with the inventors of the startups to get the patent applications granted as patents and file any desired continuations that will maximize the overall value of patent portfolio to a big tech company.
For details see the Wall Street Journal article: Zetta Research Finds Friendlier Approach to Patent Business
Copyright © 2012 Robert Moll. All rights reserved.