yes, when you convert, there is interest charge applies. the charge is as per mentioned above your post.

not everyone can get to purchase the sale item at the special price.
yes, it's like a lucky draw contest.

the example is in the pic above:

1) for rm500 conversion,
rm500+4.5% for 6 months = rm522.50; monthly instalment for 6 months = rm87.08 per month
rm500+9.0% for 12 months = rm545.00; monthly instalment for 12 months = rm45.42 per month

2) for rm3,000 conversion,
rm3,000+4.5% for 6 months = rm3,135.00; monthly instalment for 6 months = rm522.50 per month
rm3,000+9.0% for 12 months = rm3,270.00; monthly instalment for 12 months = rm272.50 per month
rm3,000+13.5% for 18 months = rm3,405.00; monthly instalment for 18 months = rm189.17 per month

3) for rm5,000 conversion,
rm5,000+4.5% for 6 months = rm5,225.00; monthly instalment for 6 months = rm870.83 per month
rm5,000+9.0% for 12 months = rm5,450.00; monthly instalment for 12 months = rm454.17 per month
rm5,000+13.5% for 18 months = rm5,675.00; monthly instalment for 18 months = rm315.28 per month
rm5,000+18.0% for 18 months = rm5,900.00; monthly instalment for 24 months = rm245.83 per month

read my reply above...

1) so that users will always check out mbb site for any promo/offer/contest/etc.
2) so that users know what they have won since they are the one registered for it
3) so that to limit the number of contestants (only those who are aware of the offer and interested to participate)

it's still 7% for those who not from kl. they can always redeem rm50 with 12,500tp for gst or cash vouchers on the spot at mydin or parkson.