Another issue with newsletters is the mailing list (leaving aside that an email shot is probably better and certainly more environmentally friendly). Having spent much of my train journey to London reviewing one such list, I now understand what GIGO* means: duplications, wrong names, wrong salutations, wrong organisations, wrong addresses. . . to say nothing of the retired, the “no longer” clients and the dead. And all this in 2,300 names.
*Garbage In, Garbage Out