(EDITED BY MOD)
Anyway I too haven't read any digital SP mags but mainly because I am too lazy to go find them, if they came as a PDF attachment in an email I would be more likely to peruse them. Going fully digital probably makes good economical sense. I haven't subscribed to the physical copy although if it was an option on my membership renewal I would, same story as before, I am just too lazy to go chase it up.
I know I may be an extreme example of a lazy consumer but maybe it wouldn't be a bad idea to
1: send the PDF of the mag via email to members
2: put the option of mag subscription on the renewal forms similar to the gyfts sponsorship thingy.