my guess is that m1 needs to "incentivise" the shop/offline channel for each sale, so it's lower margin.
the online channel ensures they get all the margin. Just a guess
m1 "missing" the 2nd month at $5.90, but pushing it back to 3rd month, does not look good. This is on top of all the patterns.
even the generous sg+my data entitlement is not a strong attraction as a main line as their local 4G coverage is the poorest between ST and SH. Sure, they are about the same as Simba (in my experience), but Simba has better roaming coverage and lower price for seniors.
if used for postpaid number parking, then i guess it's ok.