Pros
What can I say? Do not go in to this job as an account manager or account executive thinking you'll work your way up to management. You won't. But don't mistake that as a bad thing. This is a startup, so there are going to be bumps in the road. Let your voice be heard, because as many people as have complained for lack of job growth, there are also the same amount of people who have worked their way from an entry level account management position to something more. So don't sit on the sidelines and complain. You see a fire, run towards it and do you best to put it out. I started here as just that, an account manager. Luckily for me I had an amazing direct manager who believed in me and had my back regardless of the amount of mistakes I've made. And trust me, I've made a lot. But she's amazing, and luckily for the company, she's still there. So go in with an open mind and understand this job can make you money (on the sales side) or be an amazing opportunity to build experience and recognition in account management. Keep your ears open and take in as much information as possible. This job will be worth your time.
Cons
As mentioned above, there is no "fast track" to management. So get your mind right before you start. The starting pay isn't great. Again, it's a start up. So either quit and complain somewhere else or understand why you're there. Be part of the solution and not part of the problem.