A study of people who tag their own content on Delicious examined the extent to which these key words reflect brand strength. 

Nam and Kannan analyzed tags for 44 US firms operating in 14 markets on the social bookmarking site Delicious between 2006-2010. 

Using a modeling technique the researchers showed that the tags provide a lot of information on the companies. 

For example, the analysis was able to predict market value and explain unusual market fluctuations. The authors suggest that social tags demonstrate brand strength,which correlates   with market changes. 

The take away. ….What average people say and choose to highlight in social media can serve as a window to the attitudes in the broad market. 

This is another example of how crowdsourcing data can be illuminating. It’s especially interesting given the limited sample that is not representative of the population or targets for these firms.