That's definitely a difficult position to be in. I would try to ignore what my friend said and still aim for management positions. Find ways to broadcast your achievements. Tell your boss, "I'm really excited about the results of my XYZ campaign. I've really seen numbers or interest go up since I introduced it." When you are in an independent position, sometimes your boss doesn't notice your accomplishments or is so bogged down with other things, that they aren't paying attention. After a time period determined by you, set up some time to talk with your boss and talk about the successful projects you have done and mention that you love working for the company and are looking for a management position. Then ask (with the assumption that manager is an attainable goal, "What do I need to do to become a manager?" Then, your boss will either tell you specific things, like "I'd like to see you increase sales by 10%" or "I'd like you to learn how to do so-and-so" OR will try to avoid the issue by saying, "there really aren't any opportunities right now" or "let's see how things go." If he gives you specific goals, go back to work, attain those goals, and go back to him and tell him that you achieved these goals by doing X, Y, and Z. Now can we talk about my promotion? If he gives you more evasive responses such as the latter, you can be extra pushy and try to get him to give you a more concrete answer as to what you have to do to be a manager or you can just start looking for a new job.
While this is all going on, I would look into positions at other companies, too.