As someone who has spent over a decade hiring sales talent, I like to see a confident and driven candidate. Confidence and drive are two of the most important skills sales people have.
Following up on your application or resume submission demonstrates both skills to the hiring manager. Consider the fact that you are often one of many applicants for the position and you're hoping to stand out. If I have 15 candidates for a position and 2-3 call me, that will definitely put them ahead of the others.
I'm looking for career and culture fit. If you are confident and believe that you deserve to be considered an outstanding candidate tell them that. It's not just, "Have you seen my resume/when might I hear back"? It's, "I really feel that I would be a fit and add value to your team." You can help me understand how the opportunity lines up with your passion and experience.
Sales careers are extremely rewarding, but involve challenging goals, prospect's objections, and stress. It takes a driven person to persist in the face of adversity. I always say that driven people don't just want to win, they have to win. They don't let an obstacle or objection stop them. They find a way through it, around it, over it until they accomplish their goal.
Good luck in your career search,