  It is well known that quantum theory forbids the exact copying of an unknown
quantum state. Therefore in broadcasting of classical information by a quantum
channel an additional contribution to the error in the decoding is expected. We
consider the optimal copying transformation which is adapted to classical
information transmission by two linearly independent quantum states, and show
that there is no additional contribution to the error. Instead the clones are
correlated, and this breaks their usefulness: The entanglement increases with
non-orthogonality of the states. The capacity of the corresponding quantum
channel is considered also.
