Our firm (CB Insights) put out the report that this article references so some additional color on this.

Unfortunately, there is no data to support PG's assertion above (or refute it) about most acquisitions are HR acquisitions so I won't try to address that part of his comment.

The power law is real. Only 0.35% of private tech company acquisitions in 2012 were > $1B (8 of 2277). And more than 50% were less than $50M and more than 80% were less than $200M (of those with disclosed values).

If you really like graphs, the full report is here - http://www.cbinsights.com/reports/Private%20Tech%20Company%2...