Malaysia-based AirAsia already flies to Colombo offering a higher fare.
Though fares are cheaper to Bangkok, higher visa fees for Sri Lankans make Bangkok a less attractive hub to enter the point-to-point carriers' network.
A double entry visa to Thailand costs as much as 70 US dollars compared to a less than 5 dollars to Malaysia.
The budget airline started the flights in March just as Sri Lanka's currency fell from around 113 to 130 rupees to the US dollar following sustained sterilized foreign exchange sales by the Central Bank.
Exchange rate depreciation cuts real wages of salary earners and also destroys lifetime savings, impoverishing people.But Sri Lanka is now attracting more tourists after the end of a 30-year war.