It would be really nice if the books purchased through Roll20 were readable as a book (pdf type format?). As a DM (5e) one of my favorite ways to get new ideas is flipping through the DMG or monster manual and finding new monsters and rules/ideas to implement into my game. However, the way the compendium is set up, it is nearly impossible to do this since you need to search key words. The work around is to buy the physical books in addition to buying them on roll20 (the monster stat-blocks in particular are super useful) however this is a very expensive option, and personally I don't want to have to pay twice for the same content. My suggestion is to have purchased books accessible in book format through roll20 (either in game or out of game).