The digital media “industry” is moving fast and fusing itself into other traditional industries. The former categorization of device manufacture, content development and software seems to all be mixed up and jumbled — and then you add the mobile aspect and it’s hard to say what industries are what and how you size it and understand what is relevant.
I have always been a fan of Mary Meeker and came across her recent presentation of the state of the mobile world. Attached are her 50+ slides that is well worth the read.