It isn't everyday that in-depth research is done on collaboration (especially online collaboration tools) and it's effectiveness.
From the report:
"This study is the first global study to determine a model for measuring return on collaboration (ROC). It provides clear evidence demonstrating a continuum of collaboration-driven performance, such that the deployment and usage of progressively more advanced IP-enabled collaboration technology yields increasing levels of organizational performance. In May, 2009, we administered an online survey to a total of 3,662 managerial-level and above individuals in organizations in three geographic regions..."
Full PDF download available here. Disclaimer: Report sponsored by Cisco and Verizon.
Also check out:
The State of Workforce Technology Adoption: US Benchmark 2009 (Forrester $1749)