http://m.techcrunch.com/2011/03/25/search-googles-castle-moat/?p=1&icid=art_prev This is an exceptionally insightful article.
In essence, it postulates that Google isn't going into new products (Android OS, YouTube, Gmail, Goggles, etc) to grow its market share.
It's primarily a defensive tactic to protect web search.
Search engines on all their products, like Android, are Google (of course).
Gmail gives Google a better idea of who you are and lets them know which ads to serve you when you are Googling.
Everything goes back to search.
This got me asking thinking.
What is your business' core business? Its core strength?
And what can you do, peripherally, to protect the interests of your core business?
Say you were a pharmaceutical firm ReX, and your core strength was quality drugs.
ReX might enter unrelated industries of ReX gyms, a chain of clinics, ReX health insurance, to protect your core business of drugs.
All, if not the bulk of medicines and cures offered at all centres will be, obviously, ReX.
Personal example:
My core 'business', my forte, is creativity.
To protect my core, I offer strategy, write papers, teach, give talks,
I may enter other fields like design, music or write a book.
These "moats" will, however subtly or explicitly, discourage competitors and be a platform for my "castle" of creativity.