Legal and other professional publishers act as if they believe they have all the content they need. Hence the current goal is to repurpose the content they already have. In Ever Cuddled an Aardvark? Ever Studied Zymurgy? (Slaw), Robert McKay reviews this repurposing trend. Highly recommended.
Of course, what this means is that legal and other professional publishers do not want to spend money to acquire new content (and, in some cases, do not have the editorial staff to develop it). — Joe