Are you aware of the e-shopping site called Shoppe? This platform was first launched in Singapore in 2015 then reached to Malaysia, Thailand, Taiwan, Indonesia, Vietnam and the Philippines. Basically covering the south east asia. It got me thinking how Uber accepted bitcoin and I wondered if is it possible that e-shopping site accepts bitcoin?
Maybe not. Shopee is known for very cheap items and I doubt there will be people wanting to pay in bitcoin. And is bitcoin that big in south east asia? But I thought that if bitcoin gets accepted in shopee, it will be a huge sign of adoption.
There's good chance that online you have mentioned would add Bitcoin on their payment options, but this will only happen if there's good adoption happens on said countries on which they are operating.
Accepting those currencies that many people use is great advantage for their platform since they can make the e shopping experience of people became more easier.
But since that merchant is not accepting Bitcoin for now maybe try to check this site which compiled those stores that accept Bitcoin
https://www.bitpay.com/directory maybe people could see their favorite online store listed here.