I was hired as a mid-level developer into a large company to work on a product with great feedback from its users. The original authors were bootstrapped and built a great tool. Unfortunately, their lack of experience manifested itself in classic ways: performance pitfalls, maintenance difficulties, etc. (Not deriding their effort, they got further than most programmers ever do. :) )
However, with a bit of experience under my belt I was able to make meaningful contributions that impacted on our feedback and order rate in positive ways. Things took off and worked out in a great way. Times were good and so was the team.
Since then, everyone has been promoted or moved on and I'm the last teammate supporting the product. Preorders for the next release have already made it hugely profitable (10x over). Though I've been filling the role of Lead Developer/Architect/etc, I am still getting paid my original mid-level wage. My company doesn't do "bonuses", and our raise-policy prohibits more than x% per year.
With a big launch coming up, would it be unprofessional to approach management with the sales figures and ask for a (substantial) increase in pay with promotion?