Last month Forrester published a report on the group travel market titled "How Travel eBusiness Can Better Serve The Small Leisure Group Segment." Here's their summary:
"Forty-six percent of US online leisure travelers are group travelers — those who have taken at least one group trip with others outside their immediate household. While the travel industry has focused the majority of its group booking strategies and technologies on groups of 10 or more travelers, a very important group has been underserved and ignored: the small group market. Thirty percent of group trips are composed of small groups of five to nine travelers. Small group travelers are more likely to research and book travel online when compared with larger groups of 10 or more travelers, making them a very attractive online audience."
You can get your copy at Forrester.com.
Looking for more information on the group travel market? Check out:
A recent study from Orbitz.
This summary of PhoCusWright's 2007 Groups & Meetings report.
Some early TripHub data posted way back in 2006.