With promotional emails, list hygiene and quality is important. Things like market or industry are not in my experience. What's important is the content of the email, starting with the oh-so-important subject line.
I've had open rates as high as 47%, click through rates in the mid 20's and conversion in the low teens. This is very much the exception. I'm only sharing this because it is achievable. A lot of thought went into these campaigns and there is an element of luck or good timing. I've had my share of campaigns with open rates in the single percentage points, zero click through and zero conversion range.
I would say that 20-30% open, 5-10% click through and 3-5% conversion would be considered extremely successful in today's environment.