per second billing is only advantageous if the majority of your calls are under 1 minute as the per second charge costs more when it comes to 1 minute.
Eg: Hutch claims per second rate is 2 cents.
so 0.2 x 60 = 1.20 for a minute.
but per minute rate is 1.00 (TRC regulation)
So if the call is 1 minute or more, you pay more than the per minute rate.