My friend, a margin like that would make most business's jealous. In a nutshell, what it means is the percentage of profit measured against the income of the business.
For example: If your sales are $100,000, and ALL your expenses are $43,000, then your operating margin is $57,000. That profit of $57,000 represents a margin of 57% when measured against your gross sales.
Don't want to get too technical, so hope my example explains your question. And, once again, a margin like that creates envy.
Just for the record, I am an Accountant.
Cheers and continuing good luck.