seeing how Rolando is off playing in the sand. the answer to your question is as with any profeesion. the money is at the top. the thing you have to remember is that glamour photograohy is but 1 aspect of our craft. it is very hard unless you are on the top of the heap to shoot nothing but glamour and nothing else.
so you wanted to know about glamour photography in particular. so the top of glamour is being published (regularly) in major rags or covering major events. examples of success
evid Mecey, Andy Pearlman, Rolando, and many many more experts who's names you will find here on GG.
And how do you get to the top? wel you work hard for free sometimes, network like crazy your work by constantly shooting and shooting and shooting (that is where a lot of the TFP or workshop/seminars come into play) and lastly a little luck on your side.
the other answer that rolando will tell you is that the money is in private glamour. meaning: private clients that hire you for your professional services to produce outstanding quality, while getting paid very well for your work as well as your discression. again, fire off am email to rolando (or wait until he gets back to catch up on the forum) and he can tell you exactly how he makes a killing doing this very thing. like he told us in back in may at the philly workshop, he didnt pay for his 7 figure, 5,000sqft house/mansion in san antonio doing workshops. he does the workshops(using his words) "to spread the gospel about photography".
i hope someone more intelligent than me can fill in some of the holes about the hows/wheres/whys to help you get to the "top" if that is your goal.