I got the email as "Cyber Monday Savings" (Tuesday our time) so not sure for how long, although looks permanent (as it should be)http://www.zinio.com/gncsingles?issn=WDSF-0001&ns=usa&rf=cb120108
I logged in to my Zinio account and checked on this not long after receiving the same email re 99 cent back issues and also checked only 5 mins ago as well (at http://www.zinio.com/gncsingles?issn=0590-7337&ns=aus). Boards mag back issues appear to still be at full price (around $8.50aus) so maybe it hasn't taken effect yet. Great offer if and when it happens, will be interesting to see when a new issue is released if the old issues immediately drop in price (don't mind waiting for new issues to become back issues as Boards mag hard-copies in newsagents were always 2-3 months behind digital mag release!).
Looks like the 99 cent special offer applies to US Windsurfing mag (as well as the numerous back issues of popular mags) but not to Boards mag. What a shame!