Of course you can sell copies. My point is exactly this part of the article you've linked:
"With free software, users don't have to pay the distribution fee in order to use the software. They can copy the program from a friend who has a copy, or with the help of a friend who has network access".
"With free software, users don't have to pay the distribution fee in order to use the software. They can copy the program from a friend who has a copy, or with the help of a friend who has network access".