In the SMB world, there are often no positions "above you" to move to besides owner/operator.
In which case I tend to push for more budgetary flexibility so my "growth" comes in the form of experimenting with new technologies and attending seminars.
In a larger corporate environment, unless you're hoping to move towards managing more personnel, your growth often consists of department swapping. Moving from Help Desk/Asset Management, to Software/Network Engineer, or Net Sec. I suppose it all depends on your end game, "staying on" is a great way to specialize, but specialization can lead to a dead end. (as S.A.M. pointed out)