they don't make their money selling magazines or subscriptions, they make it selling advertising space. yes, the number of subscriptions influences the amount that they can get for advertising, but only in some demographics. i would guess that most of their income comes from boat/motor manufacturers. Therefore, their primary goal is building their number of subscriptions in the boating demographic. surfcasting as we think of it, is a small, regional market, which is why it is primarily serviced by small, regional magazines.
a yearly surf issue is a good idea in my opinion, but probably not worth it to SWS's bottom line.
Z, just keep writing books and that will take care of those long winters - both for the writer and the readers, probably more the writer
