Travala (partnered with Booking.com) is a relatively new online travel agency. You can buy the gift cards using Visa/Mastercard, AMEX and cryptocurrencies. There are no fees and the gift cards never expire.
When you want to redeem a gift card you add it to your travel credits and then make the booking. You can stack it with any promo codes if available. At the moment looks like only hotels/homes can be booked with travel credits.
Additional discounts and AVA:
You can also get an instant discount off your booking (up to 5% depending on your tier) + an additional cashback up to 7% paid in AVA credits. AVA is Travala's cryptocurrency. Refer a friend credits are also paid in AVA.
You can use AVA to pay for future Travala bookings, or as mentioned here, pay any Australian bill with AVA – electricity bills, car registration, mobile phone, credit card, school fees, rent or even a bank account. It's also accepted as payment at over 500 merchants Australia wide
Being a cryptocurrency, AVA is subject to market fluctuations so your value of AVA might increase or decrease in the future. I had about $150 worth in AVA in my account towards the start of the year and forgot about it until I received this gift card email and when I logged in there was over $1000 in there. Travala also pay an additional 24% of your AVA per annum. They can match or beat any competitors price too, up to 24 hours before check-in, although can't be used when applying promo codes on the competitors website.