THAI holds a 39% share of Nok Air - a minority holding. See:
http://www.centreforaviation.com/pro...rlines/nok-air
Mileage is a debt on the company's books, and not usually a part of a LCC's operation, which seems to want money up front for everything.
I guess that Nok is aimed at domestic
travellers, the majority of which would just want to get somewhere and are far less concerned about the 'extras' than price. As such, it is competing domestically with Air Asia and buses/trains. Air Asia also services the budget tourist market.
By way of contrast, Bangkok Airways offers a boutique, full service aimed at
tourists both international and domestic travellers. Both a FFP and lounges (for all pax!) are offered.
http://www.centreforaviation.com/pro...angkok-airways