If you want to read and learn, get Strategic Management (5th Edition, 2009) by Richard Lynch.
To theorise strategy in business, you can have an emergent or prescriptive approach by which to uphold company values, decision making and growth etc. To answer your question though, strategy is entirely an arbitrary process, dependent on a myriad of things, both internal and external to the business. In order to make a strategy work (above that of survival), you need to be able to plan and see what's going on in and around you.
It's pretty straight forward to think of something, such as no trolling and hotlinking, but there's always something there to stick a fork in it and totally change things, which you need to react to. Viva La Revolución.