A friend of mine who was a more than capable woodworker and builder once said, "Being a professional means knowing what you can get away with". He was not one to cut corners but he knew what his standards were and how to achieve them in his work efficiently.
In the same vein a New Hampshire boatbuilder named Bud Macintosh was quoted as saying, "Being an oldtimer in a miserable occupation like this means you've learned the balance between how good it should be and what they'll pay for, and how good it has to be before you lose your reputation."
Amateurs can shoot for the moon and take as much time as they need to get there. Most pros have to reach the moon on a budget, ignore the budget and hope to get paid anyway, or settle for sublunar orbit.
As far as being given credit for being a professional on a forum like this, I think you earn credit for the value of the work you show and advice you offer. After all, "On the internet, nobody knows you're a dog."