You must have both the technical and the marketing skill. You can find several resources online on how you can improve your marketing and technical skill. You can visit the forums, read e-books as well as marketing blogs.
Putting what you have learned into practice is just like trial and error. It is a lengthy process because it requires you to evaluate the validity and the reliability of the advices to you get along the way.
Amidst of this, it is still possible to take care both technical and marketing challenges. Learn from the experts. Educating yourself may be helpful, but you will also need advice from the expert. Grab the opportunity to learn from an expert, and develop your own technical and marketing skills.