Reading variety of magazines is a sure fire way to realize the potential areas of domain investing. Off late I have started collecting magazines of all sorts and often I go through the advertising copy contained in any particular magazine. This habit is helping me to understand the companies, their products, what is trademarked and what is a generic term.
Take for example a computer magazine, you will find many generic terms like cloud computing, data reliability, database, software, hardware, etc and together some registerd trademarks too of well established corporations.
A domain investor must catch a phrase or a word, do the google search and run the adword tool to know its potential and it it is available then it makes sense to get it registered