What's the difference between:
Manager: "Stay with me, keep doing what you are doing and I'll take care of you"
You: "But I've been doing this job for a long time and this other opportunity looks like it can be good for me and I'd like to go do it"
Manager: "That's what you think but I'll be able to give you more responsibility in this role over time and within 6 months I'll be able to promote you".
"Follow the cards and tell me where the Queen is".
Don't make the second bet and be very, very thoughtful before you take the first bet.
You have to ask yourself if your manager has the same interest and commitment to you career as you do. S/he should, but it isn't always the case.
Why? Because your manager is a human being, someone who just might have her/his career interest ahead of yours. Whenever someone moves out of a job, it is a challenge to find qualified backfill and get that person up to speed. It is so easy, so convenient to have you just stay. So you might hear the words about your career, but you have to judge the sincerity.
Also, keep in mind that staying in the same place isn't necessary the right approach for growing your career. Breadth of experience can count for a lot and you should also think about avoiding stagnation. Take the long view when thinking about a job change. Leverage your mentors and perhaps even trust them more than your manager.
[Some negative vibes here and I'm sorry. Some managers really do take the broader view and care about your career as much as you do. They also could take a broader view than you would be able to. As I've said before generalities are tough - but I still like the message of this post.]
Nonetheless, you have to decide what is important in your career. Only you are able to think about the job and your career and also put it in context of your personal life choices. When bringing life into the thinking, there is no right answer, except your answer!
Queen Photo Credit: Voxtheory
Cups and Balls Photo Credit: Wahlander