I recently found a a paper with 72 different definitions of marketing for small businesses. I prefer a simple one along the lines of Jason falls;
"Marketing is real simple for small businesses - persuading people to do something they otherwise would not"
The first key element of marketing strategy is to understand your products/services from a customer perspective. There a number of techniques to help with this:
-FAB Analysis (Features, Advantages ,Benefits)
-CVP (Customer Value Proposition)
These should form the basis of your core marketing messages
The second element is to identify who your customer, and potential customers, are. These are often called the target markets. There are several approaches to classifying customers:
Socio demographic groups
The characteristics of these groups are the basis for the alignment of marketing messages.
In my experience Markets/Competitors this is the most neglected part of marketing.
Understanding markets is not complex but involves collecting a wide variety of intelligence and forming an informed view.
Understanding competitors is more straight forward, as competitors publish their marketing materials in brochures and websites and price lists etc! It is recommended that these are analysed to identify their marketing strategies, These can be used to identify your own unique positioning or USP.
The principles of marketing are quite simple. it is the selection and implementation of the tactics of marketing that renders it complex.