500billion influence impressions per year.

The State of Online Word of Mouth Marketing

The Forrester research study found 256 billion influence impressions occurring per year. Influence posts were numbered at 1.64 billion per year. This accounted for generating another 250 billion impressions. So, people are making 500 billion influence impressions on one another about products and services every year.Source: Forrester Research, Inc. - http://www.joernstraten.com