I pretty much agree with Shawn, who seems to have the consensus opinion.
I've been training in BJJ for roughly 6 months now, and have yet to earn my first stripe on my whit belt. I've missed about a month or so due to injuries, however, i competed in an in house tournament(lost), and consistently tap out 1 and 2 stripe white belts. I've also submitted 2 blue belts. I cant fathom why i haven't earned my stripe yet. My Academy is quite large (Gracie Barra) so we don't always get the most individual attention, however guys that have joined well after me, have already received their first stripes. guys that i still tap out. I definitely don't want to bring it up to my professor as that would be whiny and disrespectful, i know a stripe is just a piece of tape but it would be nice to be recognized for my effort. Any ideas or comments would be greatly appreciated.
My friends complain to me about not getting stripes all the time. I honestly don't care that much about rank advancement, and my tolerance for people who complain about it is pretty low is a result.
For me, if you work hard, if you really master the skills, and you compete and win on a regular basis, you can establish yourself in the gym in such a way that, regardless of how big the gym is, the work will be noticed.
I don't know what your instructor's criteria is for promotion, but if you work your ass off in the gym, chances are you'll run into it eventually. Until then, focus on the skills. Those are more important anyway.