I don't really believe in that staying on one place for a long time is bad for the career. All companies want people that are productive and in the end deliver results. For me it's more about the actual tasks and the challenges the job brings that decides whether I'm happy where I am or I should get going. When I read your question I wonder more what the actual reason is why you wonder about a new job, the "whys" will give you the answer you need if the future on the company is going to keep you happy. Staying at company just for the large paycheck is not what I believe motivates anyone or making anyone truly happy.
I love my work and the company I work for. It challenges me almost everyday and I get to spend time with funny, smart people who wants so improve themselves and the work they do. It's awesome!
My tip to you is to look more about the tasks your doing and ask yourself if they motivate you, if the challenge you, if they make you feel happy. Do they? If not, look for another job because it the only good part is the salary then I'll promise you that you get stuck there for years and the day will come then you see that you have a rich pocket but a much much less richer life. And in the day it's the rich life we all want.
Hope my advice get's your thoughts spinning a bit. If not, read what I wrote again until you realize we all deserve to be happy and motivated all day long whether we are at home or at work. And that joyful life is more about me and my choices than if I work for one single company all life or a hundred different.
I don't know if this was the answer you where looking for, but I hope it helped you some. I don't think anyone can really tell you what to do or not, that is a decision for yourself. That's why my answer was more focused on your ability to know get to know yourself rather than what everyone else is doing!