Rebates or Points?

Today I am thinking of buying something on rakuten singapore. Many things are currently on sale and to add to the nudge is a S$15 off a minimum purchase of $50.

After the discount, you would be paying S$35 but they will still give you points for your purchase at 1 point per dollar spent. Which means you still get 50 points for your $35 purchase! There's also free shipping now for different deals and amounts.

Now if you also use mastercard for your purchase, you will get 10 times the number of points usually given. So your $35 purchase would give you 500 points, equivalent to $5 which can be used to b a future product. Points will be credited about 7 or so days after the purchase.

But from what I read online, it seems you cannot use the points to partially pay for a single item. So if i wanted to buy a $6 item in future, I cannot use my 500 points (or $5 credit) and just pay $1 using my credit card. It has to be an item that is $5 or less. And I won't know when these promo points expire till I get them.

I also have the personal option of paying with the OCBC frank card which gives me a 6% rebate off online purchases (minimum spend of S$500 online). This works out to S$2.10 rebate for a S$35 purchase.

Which would you choose?

I would normally go for the rebate since I don't know if I will buy anything on the site again. That said, they are giving new sign ups $10 credit which you can use by entering a code (one can use one code per bill so I would recommend the cny $15 discount which expires tonight!). So I might return to get some ramen or something if they offer free (conditional) shipping again.

I also am forgetful so I might lose my credit as I did with groupon. I just discovered I lost $20 credit from refunds etc which expired in 2012. Oh well. Haha!

So, which would you choose?