Marketing guru Seth Godin has great advice for anyone looking to make a career change. Instead of wondering how you can change from one career to another, Seth advises you just do it.
My answer is easy to write, harder to implement. In my experience the single best way to become a marketer is to market. And since marketing isn't expensive any longer (it takes more guts than money), there's no need to work for Procter & Gamble. None. In the old days, you could argue that you needed to apprentice with an expert and that you needed access to millions (or billions) to spend. No longer.
So, start your own gig. Even if you're 12 years old, start a store on eBay. You'll learn just about everything you need to learn about digital marketing by building an electronic storefront, doing permission-based email campaigns, writing a blog, etc.
This is the advice I give my clients too - it's very hard to persuade someone that you can do something without evidence that you have done it.
I wrote more about making a successful career change using this method on Freeresumehelp.net. You can find the article here.

I'm Louise Fletcher. As President of 
Great advice, Louise. 18 months ago I was an account manager for a technical staffing firm. If I had wanted to be hired by an interactive marketing agency, I never would have gotten anywhere.
Instead, I started a business with my wife, drawing on ten years of sales and marketing, and today, we run a successful firm, billing more than any agency ever would have payed me.
In our particular case, these same agencies that would have looked down their noses at my resume now come to me for advice. Just do it, indeed.
Posted by: Jim Durin | March 23, 2007 at 11:47 AM