Edit: UOB Preferred Platinum Visa (PPV) now offers 4 mpd on Mileslife, making it the best card to use with the app. With this earn rate, you can stand to earn up to 7 mpd from transactions on Mileslife.
Mileslife has grown significantly over the past few months since its launch. The number of merchants eligible for the use of the app has increased to include a wider variety of establishments.
Remember that Mileslife allows you to earn miles over and above the miles earned from credit card spend tagged to the app. As of now, there are no credit cards that allow 4 mpd earn rate with the app. Hence, the best card to use would be the UOB PRVI Miles card, which gives you 1.4 mpd on top of the app.
All merchants on Mileslife for now will earn you either 1, 2 or 3 miles per S$1 spent. Adding the 1.4 mpd earn rate using the UOB PRVI Miles card, the maximum you can earn would be 4.4 mpd. The following are 3 possible scenarios that will determine whether or not you should use Mileslife to maximise the number of miles earned from any particular transaction at eligible merchants. For the purpose of this post, I will only be focusing on restaurants.
Scenario 1: S$1 = 1 mile merchants (Think carefully)
This is by far the lowest tier of merchants on Mileslife. Adding 1.4 mpd from your UOB PRVI Miles card, the most you can obtain is 2.4 mpd from the transaction, which is not far from the 2.3 you can get using your OCBC Voyage, and much lower than the 3.2 you can get using your Maybank Horizon Visa Signature card. Also, if you are able to use the contactless payment option at such merchants, you will be way below the 4 mpd you can get using your UOB Preferred Platinum Visa or OCBC Titanium Rewards (until 30 Sep 2017). Hence, S$1 = 1 mile merchants on Mileslife do not seem enticing enough.
Scenario 2: S$1 = 2 miles merchants (Worth considering)
There may be some value considering these mid-tier merchants. Adding 1.4 mpd from your UOB PRVI Miles card, you can get up to 3.4 mpd from the transaction. This already beats the OCBC Voyage (2.3 mpd) and Maybank Horizon Visa Signature (3.2 mpd). However, if you are able to use the contactless payment option, you should still ditch the app and go ahead with using your UOB Preferred Platinum Visa or OCBC Titanium Rewards (until 30 Sep 2017) to earn you 4 mpd.
Scenario 3: S$1 = 3 miles merchants (Just go for it)
Choosing these merchants will earn you up to 4.4 mpd when combining your credit card and app earn rates. This will beat all other cards in the market, so you will not have to fumble with your other cards when making payments at these establishments.
Hopefully a card or two will accept Mileslife for the 4 mpd earn rate in due course. Alternatively, another promotion, which Mileslife launches periodically, would significantly boost your miles earn rate.