However, you will find examples even within book publishing of innovating through each of the ways you’ve described.

Acquisition is common especially within the academic sector (Pearson, Wiley & McGraw Hill spring to mind). However, diversification tends to be strategically focused on enriching content, virtual learning environment, or evaluating/testing services rather than retail or distribution (such as Lexcycle and Scribd).

I’m not at all familiar with the biopharm industry but I’m guessing they don’t innovate through acquisition of pharmacies?

In academic publishing the R&D focus is likely to be a by-product of distorted market pressures, by which I mean the students are the end users but textbook adoptions and library acquisitions are driven by decisions from faculty. However, I assume this distortion also exists within biopharm as generally patients don’t write their own prescriptions.

I’d also add a 5th response seen in both the pharma world AND in book publishing- that of consolidation via merger. It’s a defensive response, but certainly it is a response to a shifting technological environment.