Marketing your startup can be a challenge, but it is one of the most important activities you must do. You have to view marketing and a broad set of activities that include not just advertising and sales, but also public/customer relations and promotions.
Here is some food for thought as you consider PR and customer relations as part of your marketing strategy for your newborn business.
Getting press for your new start up
How to use PR firms at startup
Finally a rather lengthy video on PR for Startups from Two-Side Brain.