When I was at the ACFW Conference, the question of platform came up a few times, and I suddenly realized that editing a few fancy schmanzy literary journals and being an English teacher, while impressive-sounding to people, does not constitute a platform.
Simply stated, a platform means a lot of people. People who are already reading your writing in some format, who may also be interested in reading your book. And yes, I do realize that last sentence was a fragment.
Maybe you're freelance writing for a magazine, doing public speaking in some kind of arena that's related to your book (i.e. speaking to tea parties about your book on The Joys of Tazo Tea), or writing a blog that's related to the issues or target audience your book addresses. The possibilities are endless.
Don't get discouraged if you hear "no." A lot. Many magazines will already be swamped with articles to choose from, and the same goes for newspapers and other media outlets. Just keep trying and eventually you'll hear "yes."
And while you're searching... can you let me know if you find any media interested in any articles related to Southern charm? :)