It is important to remember that marketing is an exchange. The marketer asks the consumer to perform an action (say, buying a soda), and in exchange, the marketer gives the consumer a benefit (in this case, sweet taste and a cool image). This type of exchange is true of commercial marketing, where the objective is to get people to buy something, and it is true of social marketing, where the goal can be to encourage safer or healthier behavior.
Because your target audience is unlikely to do something just because you asked, you have to think about what you are offering members of your audience. Possible offerings could be a safer community, increased property value, recreational activities for youth, or social services for residents. Remember, your offering does not always have to be something concrete.
So, what does it mean to think like a marketer? In part, it means recognizing your side of the exchange—the fact that you need to offer something. What's more, it means you should understand the basic principles of marketing, of which there are many. A few of the most important are located at right.
To begin using these principles in the real world, break down the behavior you want to change to understand what is behind it. Only then can you think about how you might change it.