Like every new prize, your book can't sustain the promotion it first garnered. Months after its release, your book needs to remain top of mind, and keeping it in the media spotlight takes effort.
When you start any relationship with clarity and communication you stand a much better chance of getting successful results with a seamless process.
As an author, the biggest thing you need to do before you approach a publisher is to build your platform. The best place to start building your platform is online.