If you distribute GPL source code with your product, then that is correct. You do not have to give the code to people who have not purchased your product, but your purchasers can give away the code.
If you distribute GPL object or executable code with your product, then, briefly, you have to either distribute the source code with the product, or if you have to make the source available for three years to anyone who requests it for no more than your cost of distributing the source.
If you distribute GPL object or executable code with your product, then, briefly, you have to either distribute the source code with the product, or if you have to make the source available for three years to anyone who requests it for no more than your cost of distributing the source.
See my longer post for more details: https://news.ycombinator.com/item?id=11218324