You can ask for money, but "demand more" is not the right way to do it. I suggest you keep a copy of the posting, and others like it, to demonstrate what the m

You can ask for money, but "demand more" is not the right way to do it. I suggest you keep a copy of the posting, and others like it, to demonstrate what the market wage is for someone with your skills. Then, after you've done something good for the company (had a successful project for example), ask for a raise using your research to support a salary proposal. You sound a little angry in your post (understandable), but being angry when you ask for a raise is bad strategy. The company did not do anything wrong by giving you what you asked for. You bargained fairly and should have done the research before accepting the job, but don't beat yourself up over it. Live and learn. If your work is worth what you're asking for, they will pay you that.