From a recruiting standpoint, we don't really think about it too much, but that could be something that a hiring manager or interviewer wants to pry into a bit. It'll depend on why you're not getting promoted (whether or not it's a choice of yours), so I'd be careful in how you explain it. Overall though, if you've been with the same company for a long time without a promotion, we tend to lean towards it being the company's fault and not necessarily your fault. The way I see it, if you're good enough that the company doesn't want to fire you, then you're an asset, whether or not you're being promoted.