Subscribe from their newsletter po. Then, when they piso fares or any promo you'll be one of the many customers who'll receive the info. :) I just did that :) You can also try Air Asia and sign up in their BIG Membership, no fees it's just a membership so you'd be informed ahead of time about their deals. One more benefit of this is that, you'll be prioritized when you book because they will give all their members 1 day ahead priority booking vs regular clients (if ever they have piso fares) :)
Sign up on their websites. They regularly email newsletters and announcements about their upcoming promos. Based on a personal experience, as a regular piso fare abanger, I mark the date of the start of the promo and wait until 12 midnight. Expect heavy traffic on the website because people are really buying for the piso fares so patience is really a virtue.
Promo terbesar expert care sudah dimulai, diskon hingga Rp.100.000 sedang berlangsung di shopee, ada juga voucher diskon 100% alias gratis bagi bunda yang beruntung. Buruan cek di https://shope.ee/9UfEMMqqTg (id-9309)
One of the easiest ways to spot a Piso Fare flight is by subscribing to airlines' Facebook pages. Sponsored ads are very powerful and can reach millions of people, including you.