Thanks for that detailed explanation.
Basic BT* is using bank's money to pay for your credit cards, keep own money to make more money.
Next is to delay the payment due dates further(BT installment can give you additional 30 or more days delay)

Say Card A statement amount RM12k due date: 30.10.16.
Use card B (eg with statement date 15.10.16), apply BT on 16.10.16 for card B to pay Card A RM12k.

Instead of  paying RM12k to card A on 30.10.16 , you only need pay RM1k-2k to card B on 5.12.16.

One step up is to take some (interest-free) cash(overpay refund) out from bank and
use that money to make more money.

Ultimately you may make the banks paying themselves round and round without using own money at all!
until the day  BT* stops, then you just need pay a total of the original RM12k you swiped,
nothing more nothing less.

Whatever further swipes you added to your cards, you need  finally pay them  all.
But the notion that the banks can continually paying amongst themselves
without you paying a single sen holds true
UNTIL the day your cards run out of credit or  BT* stops.

That is how much fun(d) you can get from BT*.

Note: BT*= zero fee zero interest BT.
I have refunds from Aeon, Citi, Ambank, PBB, UOB,MBB.

MBB is the best, well tested many times.
UOB 1st time that day, surprisingly good refunded me RM31k
via IBG without a question.
that was meant to be interest-free money , cash taken out from credit card.
not interest earned from BTs.
2 yrs ago done once, Aeon refunded RM7977  direct to my CIMB SA,
not by cheque as per record.
I have 72 cards now, need pay AF, i cut .
the only Annual Fee  i pay is for HL wise Card,
that also only RM160.......in exchange for cash rebate RM1200.