It seems the offer somehow translated to $15? I only had 2 stays (3 nights) in late December in Canada and a single night in Europe in early January, yet received two separate emails for $30 and $15 ... which if past experience is an indicator, are actually redeemable at the current exchange rate for US$ at the time of redemption! (Used the summer credits for the December stays.)
*My stays were also all BCAA member rates