I've been a PM for over 6 years now and made the transition from an IT Dev Manager. I basically made the case that I understood the product, its target customer, and the value for the company. If you can master that, you're set. Everyone has ideas for new features, but PM's balance the needs of the customer with cost to develop and value to the company. This requires that you understand the market, your competitors, and your customers. The PMs that thrive have mastered this, but more importantly, they've learned how to get the team to work together efficiently -- both the technical side as well as the management side (cutting through the political and management BS). If you are interested in becoming a product manager, know what skills you bring to the table. If you are a developer, you bring strong analytical and technical skills as well as an understanding of the technical effort required to bring a new feature to market. Probably the best skill you would need to demonstrate is judgment: which feature would bring the most value for the least cost. And then showing how would you prioritize the roadmap of features after that.