Jane, Pollstar has a service that keeps stats for artists. For a yearly subscription fee you can get that info. Venues have access to it and can get a feel for average ticket price, tickets sold, gross receipts for particular shows. www.Pollstaronline.com They also have routing opportunities for artists. How up to date the information is up to the individual artist I believe to report.
Talent Buyers for individual venues are contacted with routing opportunities. Whether they want to take advantage of them is up to them.
By directing venues to check out Joe's artist page at www.WMA.com will help educate them to who Joe is. There is a bio and video clips available. http://www.wma.com/joe%5Fbonamassa/summary/ If a venue or promoter wants to contact William Morris to check on availability they can.
It appears the profile at WM could use a little updating.